/****************************************************************************
** $Id: qt/qdatetime.cpp   3.2.2   edited Oct 6 09:58 $
**
** Implementation of date and time classes
**
** Created : 940124
**
** Copyright (C) 1992-2002 Trolltech AS.  All rights reserved.
**
** This file is part of the tools module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

#include "qplatformdefs.h"

#include "qdatetime.h"
#include "qdatastream.h"
#include "qregexp.h"

#include <stdio.h>
#ifndef Q_OS_TEMP
#include <time.h>
#endif

#if defined(Q_OS_WIN32)
#include <windows.h>
#endif

static const uint FIRST_DAY	= 2361222;	// Julian day for 1752-09-14
static const int  FIRST_YEAR	= 1752;		// ### wrong for many countries
static const uint SECS_PER_DAY	= 86400;
static const uint MSECS_PER_DAY = 86400000;
static const uint SECS_PER_HOUR = 3600;
static const uint MSECS_PER_HOUR= 3600000;
static const uint SECS_PER_MIN	= 60;
static const uint MSECS_PER_MIN = 60000;

static const short monthDays[] = {
    0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

static const char * const qt_shortMonthNames[] = {
	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

#ifndef QT_NO_DATESTRING
/*****************************************************************************
  Some static function used by QDate, QTime and QDateTime
 *****************************************************************************/

// Replaces tokens by their value. See QDateTime::toString() for a list of valid tokens
static QString getFmtString( const QString& f, const QTime* dt = 0, const QDate* dd = 0, bool am_pm = FALSE )
{
    if ( f.isEmpty() )
	return QString::null;

    QString buf = f;

    if ( dt ) {
	if ( f == "h" ) {
	    if ( ( am_pm ) && ( dt->hour() > 12 ) )
		buf = QString::number( dt->hour() - 12 );
	    else if ( ( am_pm ) && ( dt->hour() == 0 ) )
		buf = "12";
	    else
		buf = QString::number( dt->hour() );
	} else if ( f == "hh" ) {
	    if ( ( am_pm ) && ( dt->hour() > 12 ) )
		buf = QString::number( dt->hour() - 12 ).rightJustify( 2, '0', TRUE );
	    else if ( ( am_pm ) && ( dt->hour() == 0 ) )
		buf = "12";
	    else
		buf = QString::number( dt->hour() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "m" ) {
	    buf = QString::number( dt->minute() );
	} else if ( f == "mm" ) {
	    buf = QString::number( dt->minute() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "s" ) {
	    buf = QString::number( dt->second() );
	} else if ( f == "ss" ) {
	    buf = QString::number( dt->second() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "z" ) {
	    buf = QString::number( dt->msec() );
	} else if ( f == "zzz" ) {
	    buf = QString::number( dt->msec() ).rightJustify( 3, '0', TRUE );
	} else if ( f == "ap" ) {
	    buf = dt->hour() < 12 ? "am" : "pm";
	} else if ( f == "AP" ) {
	    buf = dt->hour() < 12 ? "AM" : "PM";
	}
    }

    if ( dd ) {
	if ( f == "d" ) {
	    buf = QString::number( dd->day() );
	} else if ( f == "dd" ) {
	    buf = QString::number( dd->day() ).rightJustify( 2, '0', TRUE );
	} else if ( f == "M" ) {
	    buf = QString::number( dd->month() );
	} else if ( f == "MM" ) {
	    buf = QString::number( dd->month() ).rightJustify( 2, '0', TRUE );
#ifndef QT_NO_TEXTDATE
	} else if ( f == "ddd" ) {
	    buf = dd->shortDayName( dd->dayOfWeek() );
	} else if ( f == "dddd" ) {
	    buf = dd->longDayName( dd->dayOfWeek() );
	} else if ( f == "MMM" ) {
	    buf = dd->shortMonthName( dd->month() );
	} else if ( f == "MMMM" ) {
	    buf = dd->longMonthName( dd->month() );
#endif
	} else if ( f == "yy" ) {
	    buf = QString::number( dd->year() ).right( 2 );
	} else if ( f == "yyyy" ) {
	    buf = QString::number( dd->year() );
	}
    }

    return buf;
}

// Parses the format string and uses getFmtString to get the values for the tokens. Ret
static QString fmtDateTime( const QString& f, const QTime* dt = 0, const QDate* dd = 0 )
{
    if ( f.isEmpty() ) {
	return QString::null;
    }

    if ( dt && !dt->isValid() )
	return QString::null;
    if ( dd && !dd->isValid() )
	return QString::null;

    bool ap = ( f.contains( "AP" ) || f.contains( "ap" ) );

    QString buf;
    QString frm;
    QChar status = '0';

    for ( int i = 0; i < (int)f.length(); ++i ) {

	if ( f[ i ] == status ) {
	    if ( ( ap ) && ( ( f[ i ] == 'P' ) || ( f[ i ] == 'p' ) ) )
		status = '0';
	    frm += f[ i ];
	} else {
	    buf += getFmtString( frm, dt, dd, ap );
	    frm = QString::null;
	    if ( ( f[ i ] == 'h' ) || ( f[ i ] == 'm' ) || ( f[ i ] == 's' ) || ( f[ i ] == 'z' ) ) {
		status = f[ i ];
		frm += f[ i ];
	    } else if ( ( f[ i ] == 'd' ) || ( f[ i ] == 'M' ) || ( f[ i ] == 'y' ) ) {
		status = f[ i ];
		frm += f[ i ];
	    } else if ( ( ap ) && ( f[ i ] == 'A' ) ) {
		status = 'P';
		frm += f[ i ];
	    } else  if( ( ap ) && ( f[ i ] == 'a' ) ) {
		status = 'p';
		frm += f[ i ];
	    } else {
		buf += f[ i ];
		status = '0';
	    }
	}
    }

    buf += getFmtString( frm, dt, dd, ap );

    return buf;
}
#endif // QT_NO_DATESTRING

/*****************************************************************************
  QDate member functions
 *****************************************************************************/

/*!
    \class QDate qdatetime.h
    \reentrant
    \brief The QDate class provides date functions.

    \ingroup time
    \mainclass

    A QDate object contains a calendar date, i.e. year, month, and day
    numbers, in the modern Western (Gregorian) calendar. It can read
    the current date from the system clock. It provides functions for
    comparing dates and for manipulating dates, e.g. by adding a
    number of days or months or years.

    A QDate object is typically created either by giving the year,
    month and day numbers explicitly, or by using the static function
    currentDate(), which creates a QDate object containing the system
    clock's date. An explicit date can also be set using setYMD(). The
    fromString() function returns a QDate given a string and a date
    format which is used to interpret the date within the string.

    The year(), month(), and day() functions provide access to the
    year, month, and day numbers. Also, dayOfWeek() and dayOfYear()
    functions are provided. The same information is provided in
    textual format by the toString(), shortDayName(), longDayName(),
    shortMonthName() and longMonthName() functions.

    QDate provides a full set of operators to compare two QDate
    objects where smaller means earlier and larger means later.

    You can increment (or decrement) a date by a given number of days
    using addDays(). Similarly you can use addMonths() and addYears().
    The daysTo() function returns the number of days between two
    dates.

    The daysInMonth() and daysInYear() functions return how many days
    there are in this date's month and year, respectively. The
    leapYear() function indicates whether this date is in a leap year.

    Note that QDate should not be used for date calculations for dates
    prior to the introduction of the Gregorian calendar. This calendar
    was adopted by England from the 14<sup><small>th</small></sup>
    September 1752 (hence this is the earliest valid QDate), and
    subsequently by most other Western countries, until 1923.

    The end of time is reached around the year 8000, by which time we
    expect Qt to be obsolete.

    \sa QTime QDateTime QDateEdit QDateTimeEdit
*/

/*!
    \enum Qt::DateFormat

    \value TextDate (default) Qt format
    \value ISODate ISO 8601 extended format (YYYY-MM-DD, or with time,
    YYYY-MM-DDTHH:MM:SS)
    \value LocalDate locale dependent format
*/


/*!
    \enum Qt::TimeSpec

    \value LocalTime Locale dependent time (Timezones and Daylight Savings Time)
    \value UTC Coordinated Universal Time, replaces Greenwich Time
*/

/*!
    \fn QDate::QDate()

    Constructs a null date. Null dates are invalid.

    \sa isNull(), isValid()
*/


/*!
    Constructs a date with year \a y, month \a m and day \a d.

    \a y must be in the range 1752..8000, \a m must be in the range
    1..12, and \a d must be in the range 1..31.

    \warning If \a y is in the range 0..99, it is interpreted as
    1900..1999.

    \sa isValid()
*/

QDate::QDate( int y, int m, int d )
{
    jd = 0;
    setYMD( y, m, d );
}


/*!
    \fn bool QDate::isNull() const

    Returns TRUE if the date is null; otherwise returns FALSE. A null
    date is invalid.

    \sa isValid()
*/


/*!
    Returns TRUE if this date is valid; otherwise returns FALSE.

    \sa isNull()
*/

bool QDate::isValid() const
{
    return jd >= FIRST_DAY;
}


/*!
    Returns the year (1752..8000) of this date.

    \sa month(), day()
*/

int QDate::year() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return y;
}

/*!
    Returns the month (January=1..December=12) of this date.

    \sa year(), day()
*/

int QDate::month() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return m;
}

/*!
    Returns the day of the month (1..31) of this date.

    \sa year(), month(), dayOfWeek()
*/

int QDate::day() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return d;
}

/*!
    Returns the weekday (Monday=1..Sunday=7) for this date.

    \sa day(), dayOfYear()
*/

int QDate::dayOfWeek() const
{
    return ( jd % 7 ) + 1;
}

/*!
    Returns the day of the year (1..365) for this date.

    \sa day(), dayOfWeek()
*/

int QDate::dayOfYear() const
{
    return jd - gregorianToJulian(year(), 1, 1) + 1;
}

/*!
    Returns the number of days in the month (28..31) for this date.

    \sa day(), daysInYear()
*/

int QDate::daysInMonth() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    if ( m == 2 && leapYear(y) )
	return 29;
    else
	return monthDays[m];
}

/*!
    Returns the number of days in the year (365 or 366) for this date.

    \sa day(), daysInMonth()
*/

int QDate::daysInYear() const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    return leapYear( y ) ? 366 : 365;
}

/*!
  Returns the week number (1 to 53), and stores the year in \a
  *yearNumber unless \a yearNumber is null (the default).

  Returns 0 if the date is invalid.

  In accordance with ISO 8601, weeks start on Monday and the first
  Thursday of a year is always in week 1 of that year. Most years
  have 52 weeks, but some have 53.

  \a *yearNumber is not always the same as year(). For example, 1
  January 2000 has week number 52 in the year 1999, and 31 December
  2002 has week number 1 in the year 2003.

  \sa isValid()
*/

int QDate::weekNumber( int *yearNumber ) const
{
    if ( !isValid() )
	return 0;

    int dow = dayOfWeek();
    int doy = dayOfYear();
    int currYear = year();
    int jan1WeekDay = QDate( currYear, 1, 1 ).dayOfWeek();
    int yearNum;
    int weekNum;

    if ( doy <= (8 - jan1WeekDay) && jan1WeekDay > 4 ) {
	yearNum = currYear - 1;
	weekNum = 52;
	if ( jan1WeekDay == 5 ||
	     (jan1WeekDay == 6 && QDate::leapYear(yearNum)) )
	    weekNum++;
    } else {
	int totalDays = 365;
	if ( QDate::leapYear(currYear) )
	    totalDays++;

	if ( (totalDays - doy < 4 - dow)
	     || (jan1WeekDay == 7 && totalDays - doy < 3) ) {
	    yearNum = currYear + 1;
	    weekNum = 1;
	} else {
	    int j = doy + ( 7 - dow ) + ( jan1WeekDay - 1 );
	    yearNum = currYear;
	    weekNum = j / 7;
	    if ( jan1WeekDay > 4 )
		weekNum--;
	}
    }
    if ( yearNumber )
	*yearNumber = yearNum;
    return weekNum;
}

/*!
  \fn QString QDate::monthName( int month )
  \obsolete

  Use shortMonthName() instead.
*/
#ifndef QT_NO_TEXTDATE
/*!
    Returns the name of the \a month.

    1 = "Jan", 2 = "Feb", ... 12 = "Dec"

    The month names will be localized according to the system's locale
    settings.

    \sa toString(), longMonthName(), shortDayName(), longDayName()
*/

QString QDate::shortMonthName( int month )
{
#if defined(QT_CHECK_RANGE)
    if ( month < 1 || month > 12 ) {
	qWarning( "QDate::shortMonthName: Parameter out ouf range" );
	month = 1;
    }
#endif
#ifndef Q_WS_WIN
    char buffer[255];
    tm tt;
    memset( &tt, 0, sizeof( tm ) );
    tt.tm_mon = month - 1;
    if ( strftime( buffer, sizeof( buffer ), "%b", &tt ) )
	return QString::fromLocal8Bit( buffer );
#else
    SYSTEMTIME st;
    memset( &st, 0, sizeof(SYSTEMTIME) );
    st.wYear = 2000;
    st.wMonth = month;
    st.wDay = 1;
    const wchar_t mmm_t[] = L"MMM"; // workaround for Borland
    QT_WA( {
	TCHAR buf[255];
	if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, mmm_t, buf, 255 ) )
	    return QString::fromUcs2( (ushort*)buf );
    } , {
	char buf[255];
	if ( GetDateFormatA( LOCALE_USER_DEFAULT, 0, &st, "MMM", (char*)&buf, 255 ) )
	    return QString::fromLocal8Bit( buf );
    } );
#endif
    return QString::null;
}

/*!
    Returns the long name of the \a month.

    1 = "January", 2 = "February", ... 12 = "December"

    The month names will be localized according to the system's locale
    settings.

    \sa toString(), shortMonthName(), shortDayName(), longDayName()
*/

QString QDate::longMonthName( int month )
{
#if defined(QT_CHECK_RANGE)
    if ( month < 1 || month > 12 ) {
	qWarning( "QDate::longMonthName: Parameter out ouf range" );
	month = 1;
    }
#endif
#ifndef Q_WS_WIN
    char buffer[255];
    tm tt;
    memset( &tt, 0, sizeof( tm ) );
    tt.tm_mon = month - 1;
    if ( strftime( buffer, sizeof( buffer ), "%B", &tt ) )
	return QString::fromLocal8Bit( buffer );
#else
    SYSTEMTIME st;
    memset( &st, 0, sizeof(SYSTEMTIME) );
    st.wYear = 2000;
    st.wMonth = month;
    st.wDay = 1 ;
    const wchar_t mmmm_t[] = L"MMMM"; // workaround for Borland
    QT_WA( {
	TCHAR buf[255];
	if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, mmmm_t, buf, 255 ) )
	    return QString::fromUcs2( (ushort*)buf );
    } , {
	char buf[255];
	if ( GetDateFormatA( LOCALE_USER_DEFAULT, 0, &st, "MMMM", (char*)&buf, 255 ) )
	    return QString::fromLocal8Bit( buf );
    } )
#endif

    return QString::null;
}

/*!
  \fn QString QDate::dayName( int weekday )
  \obsolete

  Use shortDayName() instead.
*/

/*!
    Returns the name of the \a weekday.

    1 = "Mon", 2 = "Tue", ... 7 = "Sun"

    The day names will be localized according to the system's locale
    settings.

    \sa toString(), shortMonthName(), longMonthName(), longDayName()
*/

QString QDate::shortDayName( int weekday )
{
#if defined(QT_CHECK_RANGE)
    if ( weekday < 1 || weekday > 7 ) {
	qWarning( "QDate::shortDayName: Parameter out of range" );
	weekday = 1;
    }
#endif
#ifndef Q_WS_WIN
    char buffer[255];
    tm tt;
    memset( &tt, 0, sizeof( tm ) );
    tt.tm_wday = ( weekday == 7 ) ? 0 : weekday;
    if ( strftime( buffer, sizeof( buffer ), "%a", &tt ) )
	return QString::fromLocal8Bit( buffer );
#else
    SYSTEMTIME st;
    memset( &st, 0, sizeof(SYSTEMTIME) );
    st.wYear = 2001;
    st.wMonth = 10;
    st.wDayOfWeek = ( weekday == 7 ) ? 0 : weekday;
    st.wDay = 21 + st.wDayOfWeek;
    const wchar_t ddd_t[] = L"ddd"; // workaround for Borland
    QT_WA( {
	TCHAR buf[255];
	if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, ddd_t, buf, 255 ) )
	    return QString::fromUcs2( (ushort*)buf );
    } , {
	char buf[255];
	if ( GetDateFormatA( LOCALE_USER_DEFAULT, 0, &st, "ddd", (char*)&buf, 255 ) )
	    return QString::fromLocal8Bit( buf );
    } );
#endif

    return QString::null;
}

/*!
    Returns the long name of the \a weekday.

    1 = "Monday", 2 = "Tuesday", ... 7 = "Sunday"

    The day names will be localized according to the system's locale
    settings.

    \sa toString(), shortDayName(), shortMonthName(), longMonthName()
*/

QString QDate::longDayName( int weekday )
{
#if defined(QT_CHECK_RANGE)
    if ( weekday < 1 || weekday > 7 ) {
	qWarning( "QDate::longDayName: Parameter out of range" );
	weekday = 1;
    }
#endif
#ifndef Q_WS_WIN
    char buffer[255];
    tm tt;
    memset( &tt, 0, sizeof( tm ) );
    tt.tm_wday = ( weekday == 7 ) ? 0 : weekday;
    if ( strftime( buffer, sizeof( buffer ), "%A", &tt ) )
	return QString::fromLocal8Bit( buffer );
#else
    SYSTEMTIME st;
    memset( &st, 0, sizeof(SYSTEMTIME) );
    st.wYear = 2001;
    st.wMonth = 10;
    st.wDayOfWeek = ( weekday == 7 ) ? 0 : weekday;
    st.wDay = 21 + st.wDayOfWeek;
    const wchar_t dddd_t[] = L"dddd"; // workaround for Borland
    QT_WA( {
	TCHAR buf[255];
	if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, dddd_t, buf, 255 ) )
	    return QString::fromUcs2( (ushort*)buf );
    } , {
	char buf[255];
	if ( GetDateFormatA( LOCALE_USER_DEFAULT, 0, &st, "dddd", (char*)&buf, 255 ) )
	    return QString::fromLocal8Bit( buf );
    } );
#endif

    return QString::null;
}
#endif //QT_NO_TEXTDATE

#ifndef QT_NO_DATESTRING

#if !defined(QT_NO_SPRINTF)
/*!
    \overload

    Returns the date as a string. The \a f parameter determines the
    format of the string.

    If \a f is \c Qt::TextDate, the string format is "Sat May 20 1995"
    (using the shortDayName() and shortMonthName() functions to
    generate the string, so the day and month names are locale
    specific).

    If \a f is \c Qt::ISODate, the string format corresponds to the
    ISO 8601 specification for representations of dates, which is
    YYYY-MM-DD where YYYY is the year, MM is the month of the year
    (between 01 and 12), and DD is the day of the month between 01 and
    31.

    If \a f is \c Qt::LocalDate, the string format depends on the
    locale settings of the system.

    If the date is an invalid date, then QString::null will be returned.

    \sa shortDayName(), shortMonthName()
*/
QString QDate::toString( Qt::DateFormat f ) const
{
    if ( !isValid() )
	return QString::null;
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    switch ( f ) {
    case Qt::LocalDate:
	{
#ifndef Q_WS_WIN
	    tm tt;
	    memset( &tt, 0, sizeof( tm ) );
	    char buf[255];
	    tt.tm_mday = day();
	    tt.tm_mon = month() - 1;
	    tt.tm_year = year() - 1900;

	    static const char * avoidEgcsWarning = "%x";
	    if ( strftime( buf, sizeof(buf), avoidEgcsWarning, &tt ) )
		return QString::fromLocal8Bit( buf );
#else
	    SYSTEMTIME st;
	    memset( &st, 0, sizeof(SYSTEMTIME) );
	    st.wYear = year();
	    st.wMonth = month();
	    st.wDay = day();
	    QT_WA( {
		TCHAR buf[255];
		if ( GetDateFormat( LOCALE_USER_DEFAULT, 0, &st, 0, buf, 255 ) )
		    return QString::fromUcs2( (ushort*)buf );
	    } , {
		char buf[255];
		if ( GetDateFormatA( LOCALE_USER_DEFAULT, 0, &st, 0, (char*)&buf, 255 ) )
		    return QString::fromLocal8Bit( buf );
	    } );
#endif
	    return QString::null;
	}
    default:
#ifndef QT_NO_TEXTDATE
    case Qt::TextDate:
	{
	    QString buf = shortDayName( dayOfWeek() );
	    buf += ' ';
	    buf += shortMonthName( m );
	    QString t;
	    t.sprintf( " %d %d", d, y );
	    buf += t;
	    return buf;
	}
#endif
    case Qt::ISODate:
	{
	    QString month( QString::number( m ).rightJustify( 2, '0' ) );
	    QString day( QString::number( d ).rightJustify( 2, '0' ) );
	    return QString::number( y ) + "-" + month + "-" + day;
	}
    }
}
#endif //QT_NO_SPRINTF

/*!
    Returns the date as a string. The \a format parameter determines
    the format of the result string.

    These expressions may be used:

    \table
    \header \i Expression \i Output
    \row \i d \i the day as number without a leading zero (1-31)
    \row \i dd \i the day as number with a leading zero (01-31)
    \row \i ddd
	 \i the abbreviated localized day name (e.g. 'Mon'..'Sun').
	    Uses QDate::shortDayName().
    \row \i dddd
	 \i the long localized day name (e.g. 'Monday'..'Sunday').
	    Uses QDate::longDayName().
    \row \i M \i the month as number without a leading zero (1-12)
    \row \i MM \i the month as number with a leading zero (01-12)
    \row \i MMM
	 \i the abbreviated localized month name (e.g. 'Jan'..'Dec').
	    Uses QDate::shortMonthName().
    \row \i MMMM
	 \i the long localized month name (e.g. 'January'..'December').
	    Uses QDate::longMonthName().
    \row \i yy \i the year as two digit number (00-99)
    \row \i yyyy \i the year as four digit number (1752-8000)
    \endtable

    All other input characters will be ignored.

    Example format strings (assuming that the QDate is the
    20<sup><small>th</small></sup> July 1969):
    \table
    \header \i Format \i Result
    \row \i dd.MM.yyyy	  \i11 20.07.1969
    \row \i ddd MMMM d yy \i11 Sun July 20 69
    \endtable

    If the date is an invalid date, then QString::null will be returned.

    \sa QDateTime::toString() QTime::toString()

*/
QString QDate::toString( const QString& format ) const
{
    return fmtDateTime( format, 0, this );
}
#endif //QT_NO_DATESTRING

/*!
    Sets the date's year \a y, month \a m and day \a d.

    \a y must be in the range 1752..8000, \a m must be in the range
    1..12, and \a d must be in the range 1..31.

    \warning If \a y is in the range 0..99, it is interpreted as
    1900..1999.

    Returns TRUE if the date is valid; otherwise returns FALSE.
*/

bool QDate::setYMD( int y, int m, int d )
{
    if ( year() == y && month() == m && day() == d )
	return isValid();
    if ( !isValid(y,m,d) ) {
#if defined(QT_CHECK_RANGE)
	 qWarning( "QDate::setYMD: Invalid date %04d-%02d-%02d", y, m, d );
#endif
	 return FALSE;
    }
    jd = gregorianToJulian( y, m, d );
    return TRUE;
}

/*!
    Returns a QDate object containing a date \a ndays later than the
    date of this object (or earlier if \a ndays is negative).

    \sa addMonths() addYears() daysTo()
*/

QDate QDate::addDays( int ndays ) const
{
    QDate d;
    d.jd = jd + ndays;
    return d;
}

/*!
    Returns a QDate object containing a date \a nmonths later than the
    date of this object (or earlier if \a nmonths is negative).

    \sa addDays() addYears()
*/

QDate QDate::addMonths( int nmonths ) const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );

    while ( nmonths != 0 ) {
	if ( nmonths < 0 && nmonths + 12 <= 0 ) {
	    y--;
	    nmonths+=12;
	} else if ( nmonths < 0 ) {
	    m+= nmonths;
	    nmonths = 0;
	    if ( m <= 0 ) {
		--y;
		m+=12;
	    }
	} else if ( nmonths - 12 >= 0 ) {
	    y++;
	    nmonths-=12;
	} else if ( m == 12 ) {
	    y++;
	    m = 0;
	} else {
	    m+= nmonths;
	    nmonths = 0;
	    if ( m > 12 ) {
		++y;
		m -= 12;
	    }
	}
    }

    QDate tmp(y,m,1);

    if( d > tmp.daysInMonth() )
	d = tmp.daysInMonth();

    QDate date(y, m, d);
    return date;

}

/*!
    Returns a QDate object containing a date \a nyears later than the
    date of this object (or earlier if \a nyears is negative).

    \sa addDays(), addMonths()
*/

QDate QDate::addYears( int nyears ) const
{
    int y, m, d;
    julianToGregorian( jd, y, m, d );
    y += nyears;

    QDate tmp(y,m,1);

    if( d > tmp.daysInMonth() )
	d = tmp.daysInMonth();

    QDate date(y, m, d);
    return date;
}



/*!
    Returns the number of days from this date to \a d (which is
    negative if \a d is earlier than this date).

    Example:
    \code
	QDate d1( 1995, 5, 17 );  // May 17th 1995
	QDate d2( 1995, 5, 20 );  // May 20th 1995
	d1.daysTo( d2 );          // returns 3
	d2.daysTo( d1 );          // returns -3
    \endcode

    \sa addDays()
*/

int QDate::daysTo( const QDate &d ) const
{
    return d.jd - jd;
}


/*!
    \fn bool QDate::operator==( const QDate &d ) const

    Returns TRUE if this date is equal to \a d; otherwise returns FALSE.
*/

/*!
    \fn bool QDate::operator!=( const QDate &d ) const

    Returns TRUE if this date is different from \a d; otherwise returns FALSE.
*/

/*!
    \fn bool QDate::operator<( const QDate &d ) const

    Returns TRUE if this date is earlier than \a d, otherwise returns FALSE.
*/

/*!
    \fn bool QDate::operator<=( const QDate &d ) const

    Returns TRUE if this date is earlier than or equal to \a d,
    otherwise returns FALSE.
*/

/*!
    \fn bool QDate::operator>( const QDate &d ) const

    Returns TRUE if this date is later than \a d, otherwise returns FALSE.
*/

/*!
    \fn bool QDate::operator>=( const QDate &d ) const

    Returns TRUE if this date is later than or equal to \a d,
    otherwise returns FALSE.
*/

/*!
    \overload
    Returns the current date, as reported by the system clock.

    \sa QTime::currentTime(), QDateTime::currentDateTime()
*/

QDate QDate::currentDate()
{
    return currentDate( Qt::LocalTime );
}

/*!
  Returns the current date, as reported by the system clock, for the
  TimeSpec \a ts. The default TimeSpec is LocalTime.

  \sa QTime::currentTime(), QDateTime::currentDateTime(), Qt::TimeSpec
*/
QDate QDate::currentDate( Qt::TimeSpec ts )
{
    QDate d;
#if defined(Q_OS_WIN32)
    SYSTEMTIME t;
    memset( &t, 0, sizeof(SYSTEMTIME) );
    if ( ts == Qt::LocalTime )
	GetLocalTime( &t );
    else
	GetSystemTime( &t );
    d.jd = gregorianToJulian( t.wYear, t.wMonth, t.wDay );
#else
    // posix compliant system
    time_t ltime;
    time( &ltime );
    tm *t;

#  if defined(QT_THREAD_SUPPORT) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
    // use the reentrant versions of localtime() and gmtime() where available
    tm res;
    if ( ts == Qt::LocalTime )
	t = localtime_r( &ltime, &res );
    else
	t = gmtime_r( &ltime, &res );
#  else
    if ( ts == Qt::LocalTime )
	t = localtime( &ltime );
    else
	t = gmtime( &ltime );
#  endif // QT_THREAD_SUPPORT && _POSIX_THREAD_SAFE_FUNCTIONS

    d.jd = gregorianToJulian( t->tm_year + 1900, t->tm_mon + 1, t->tm_mday );
#endif
    return d;
}

#ifndef QT_NO_DATESTRING
/*!
    Returns the QDate represented by the string \a s, using the format
    \a f, or an invalid date if the string cannot be parsed.

    Note for \c Qt::TextDate: It is recommended that you use the
    English short month names (e.g. "Jan"). Although localized month
    names can also be used, they depend on the user's locale settings.

    \warning \c Qt::LocalDate cannot be used here.
*/
QDate QDate::fromString( const QString& s, Qt::DateFormat f )
{
    if ( ( s.isEmpty() ) || ( f == Qt::LocalDate ) ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QDate::fromString: Parameter out of range" );
#endif
	QDate d;
	d.jd = 0;
	return d;
    }
    switch ( f ) {
    case Qt::ISODate:
	{
	    int year( s.mid( 0, 4 ).toInt() );
	    int month( s.mid( 5, 2 ).toInt() );
	    int day( s.mid( 8, 2 ).toInt() );
	    if ( year && month && day )
		return QDate( year, month, day );
	}
	break;
    default:
#ifndef QT_NO_TEXTDATE
    case Qt::TextDate:
	{
	    /*
	      This will fail gracefully if the input string doesn't
	      contain any space.
	    */
	    int monthPos = s.find( ' ' ) + 1;
	    int dayPos = s.find( ' ', monthPos ) + 1;

	    QString monthName( s.mid(monthPos, dayPos - monthPos - 1) );
	    int month = -1;

	    // try English names first
	    for ( int i = 0; i < 12; i++ ) {
		if ( monthName == qt_shortMonthNames[i] ) {
		    month = i + 1;
		    break;
		}
	    }

	    // try the localized names
	    if ( month == -1 ) {
		for ( int i = 0; i < 12; i++ ) {
		    if ( monthName == shortMonthName( i + 1 ) ) {
			month = i + 1;
			break;
		    }
		}
	    }
#if defined(QT_CHECK_RANGE)
	    if ( month < 1 || month > 12 ) {
		qWarning( "QDate::fromString: Parameter out of range" );
		QDate d;
		d.jd = 0;
		return d;
	    }
#endif
	    int day = s.mid( dayPos, 2 ).stripWhiteSpace().toInt();
	    int year = s.right( 4 ).toInt();
	    return QDate( year, month, day );
	}
#else
	break;
#endif
    }
    return QDate();
}
#endif //QT_NO_DATESTRING

/*!
    \overload

    Returns TRUE if the specified date (year \a y, month \a m and day
    \a d) is valid; otherwise returns FALSE.

    Example:
    \code
    QDate::isValid( 2002, 5, 17 );  // TRUE   May 17th 2002 is valid
    QDate::isValid( 2002, 2, 30 );  // FALSE  Feb 30th does not exist
    QDate::isValid( 2004, 2, 29 );  // TRUE   2004 is a leap year
    QDate::isValid( 1202, 6, 6 );   // FALSE  1202 is pre-Gregorian
    \endcode

    \warning A \a y value in the range 00..99 is interpreted as
    1900..1999.

    \sa isNull(), setYMD()
*/

bool QDate::isValid( int y, int m, int d )
{
    if ( y >= 0 && y <= 99 )
	y += 1900;
    else if ( y < FIRST_YEAR || (y == FIRST_YEAR && (m < 9 ||
						    (m == 9 && d < 14))) )
	return FALSE;
    return (d > 0 && m > 0 && m <= 12) &&
	   (d <= monthDays[m] || (d == 29 && m == 2 && leapYear(y)));
}

/*!
    Returns TRUE if the specified year \a y is a leap year; otherwise
    returns FALSE.
*/

bool QDate::leapYear( int y )
{
    return y % 4 == 0 && y % 100 != 0 || y % 400 == 0;
}

/*!
  \internal
  Converts a Gregorian date to a Julian day.
  This algorithm is taken from Communications of the ACM, Vol 6, No 8.
  \sa julianToGregorian()
*/

uint QDate::gregorianToJulian( int y, int m, int d )
{
    uint c, ya;
    if ( y <= 99 )
	y += 1900;
    if ( m > 2 ) {
	m -= 3;
    } else {
	m += 9;
	y--;
    }
    c = y;					// NOTE: Sym C++ 6.0 bug
    c /= 100;
    ya = y - 100*c;
    return 1721119 + d + (146097*c)/4 + (1461*ya)/4 + (153*m+2)/5;
}

/*!
  \internal
  Converts a Julian day to a Gregorian date.
  This algorithm is taken from Communications of the ACM, Vol 6, No 8.
  \sa gregorianToJulian()
*/

void QDate::julianToGregorian( uint jd, int &y, int &m, int &d )
{
    uint x;
    uint j = jd - 1721119;
    y = (j*4 - 1)/146097;
    j = j*4 - 146097*y - 1;
    x = j/4;
    j = (x*4 + 3) / 1461;
    y = 100*y + j;
    x = (x*4) + 3 - 1461*j;
    x = (x + 4)/4;
    m = (5*x - 3)/153;
    x = 5*x - 3 - 153*m;
    d = (x + 5)/5;
    if ( m < 10 ) {
	m += 3;
    } else {
	m -= 9;
	y++;
    }
}


/*****************************************************************************
  QTime member functions
 *****************************************************************************/

/*!
    \class QTime qdatetime.h
    \reentrant

    \brief The QTime class provides clock time functions.

    \ingroup time
    \mainclass

    A QTime object contains a clock time, i.e. the number of hours,
    minutes, seconds, and milliseconds since midnight. It can read the
    current time from the system clock and measure a span of elapsed
    time. It provides functions for comparing times and for
    manipulating a time by adding a number of (milli)seconds.

    QTime uses the 24-hour clock format; it has no concept of AM/PM.
    It operates in local time; it knows nothing about time zones or
    daylight savings time.

    A QTime object is typically created either by giving the number of
    hours, minutes, seconds, and milliseconds explicitly, or by using
    the static function currentTime(), which creates a QTime object
    that contains the system's clock time. Note that the accuracy
    depends on the accuracy of the underlying operating system; not
    all systems provide 1-millisecond accuracy.

    The hour(), minute(), second(), and msec() functions provide
    access to the number of hours, minutes, seconds, and milliseconds
    of the time. The same information is provided in textual format by
    the toString() function.

    QTime provides a full set of operators to compare two QTime
    objects. One time is considered smaller than another if it is
    earlier than the other.

    The time a given number of seconds or milliseconds later than a
    given time can be found using the addSecs() or addMSecs()
    functions. Correspondingly, the number of (milli)seconds between
    two times can be found using the secsTo() or msecsTo() functions.

    QTime can be used to measure a span of elapsed time using the
    start(), restart(), and elapsed() functions.

    \sa QDate, QDateTime
*/

/*!
    \fn QTime::QTime()

    Constructs the time 0 hours, minutes, seconds and milliseconds,
    i.e. 00:00:00.000 (midnight). This is a valid time.

    \sa isValid()
*/

/*!
    Constructs a time with hour \a h, minute \a m, seconds \a s and
    milliseconds \a ms.

    \a h must be in the range 0..23, \a m and \a s must be in the
    range 0..59, and \a ms must be in the range 0..999.

    \sa isValid()
*/

QTime::QTime( int h, int m, int s, int ms )
{
    setHMS( h, m, s, ms );
}


/*!
    \fn bool QTime::isNull() const

    Returns TRUE if the time is equal to 00:00:00.000; otherwise
    returns FALSE. A null time is valid.

    \sa isValid()
*/

/*!
    Returns TRUE if the time is valid; otherwise returns FALSE. The
    time 23:30:55.746 is valid, whereas 24:12:30 is invalid.

    \sa isNull()
*/

bool QTime::isValid() const
{
    return ds < MSECS_PER_DAY;
}


/*!
    Returns the hour part (0..23) of the time.
*/

int QTime::hour() const
{
    return ds / MSECS_PER_HOUR;
}

/*!
    Returns the minute part (0..59) of the time.
*/

int QTime::minute() const
{
    return (ds % MSECS_PER_HOUR)/MSECS_PER_MIN;
}

/*!
    Returns the second part (0..59) of the time.
*/

int QTime::second() const
{
    return (ds / 1000)%SECS_PER_MIN;
}

/*!
    Returns the millisecond part (0..999) of the time.
*/

int QTime::msec() const
{
    return ds % 1000;
}

#ifndef QT_NO_DATESTRING
#ifndef QT_NO_SPRINTF
/*!
    \overload

    Returns the time as a string. Milliseconds are not included. The
    \a f parameter determines the format of the string.

    If \a f is \c Qt::TextDate, the string format is HH:MM:SS; e.g. 1
    second before midnight would be "23:59:59".

    If \a f is \c Qt::ISODate, the string format corresponds to the
    ISO 8601 extended specification for representations of dates,
    which is also HH:MM:SS.

    If \a f is Qt::LocalDate, the string format depends on the locale
    settings of the system.

    If the time is an invalid time, then QString::null will be returned.
*/

QString QTime::toString( Qt::DateFormat f ) const
{
    if ( !isValid() )
	return QString::null;

    switch ( f ) {
    case Qt::LocalDate:
	{
#ifndef Q_WS_WIN
	    tm tt;
	    memset( &tt, 0, sizeof( tm ) );
	    char buf[255];
	    tt.tm_sec = second();
	    tt.tm_min = minute();
	    tt.tm_hour = hour();
	    if ( strftime( buf, sizeof(buf), "%X", &tt ) )
		return QString::fromLocal8Bit( buf );
#else
	    SYSTEMTIME st;
	    memset( &st, 0, sizeof(SYSTEMTIME) );
	    st.wHour = hour();
	    st.wMinute = minute();
	    st.wSecond = second();
	    st.wMilliseconds = 0;
	    QT_WA( {
		TCHAR buf[255];
		if ( GetTimeFormat( LOCALE_USER_DEFAULT, 0, &st, 0, buf, 255 ) )
		    return QString::fromUcs2( (ushort*)buf );
	    } , {
		char buf[255];
		if ( GetTimeFormatA( LOCALE_USER_DEFAULT, 0, &st, 0, (char*)&buf, 255 ) )
		    return QString::fromLocal8Bit( buf );
	    } );
#endif
	    return QString::null;
	}
    default:
    case Qt::ISODate:
    case Qt::TextDate:
	QString buf;
	buf.sprintf( "%.2d:%.2d:%.2d", hour(), minute(), second() );
	return buf;
    }
}
#endif

/*!
    Returns the time as a string. The \a format parameter determines
    the format of the result string.

    These expressions may be used:

    \table
    \header \i Expression \i Output
    \row \i h
	 \i the hour without a leading zero (0..23 or 1..12 if AM/PM display)
    \row \i hh
	 \i the hour with a leading zero (00..23 or 01..12 if AM/PM display)
    \row \i m \i the minute without a leading zero (0..59)
    \row \i mm \i the minute with a leading zero (00..59)
    \row \i s \i the second whithout a leading zero (0..59)
    \row \i ss \i the second whith a leading zero (00..59)
    \row \i z \i the milliseconds without leading zeroes (0..999)
    \row \i zzz \i the milliseconds with leading zeroes (000..999)
    \row \i AP
	 \i use AM/PM display. \e AP will be replaced by either "AM" or "PM".
    \row \i ap
	 \i use am/pm display. \e ap will be replaced by either "am" or "pm".
    \endtable

    All other input characters will be ignored.

    Example format strings (assuming that the QTime is 14:13:09.042)

    \table
    \header \i Format \i Result
    \row \i hh:mm:ss.zzz    \i11 14:13:09.042
    \row \i h:m:s ap	    \i11 2:13:9 pm
    \endtable

    If the time is an invalid time, then QString::null will be returned.

    \sa QDate::toString() QDateTime::toString()
*/
QString QTime::toString( const QString& format ) const
{
    return fmtDateTime( format, this, 0 );
}
#endif //QT_NO_DATESTRING
/*!
    Sets the time to hour \a h, minute \a m, seconds \a s and
    milliseconds \a ms.

    \a h must be in the range 0..23, \a m and \a s must be in the
    range 0..59, and \a ms must be in the range 0..999. Returns TRUE
    if the set time is valid; otherwise returns FALSE.

    \sa isValid()
*/

bool QTime::setHMS( int h, int m, int s, int ms )
{
    if ( !isValid(h,m,s,ms) ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QTime::setHMS Invalid time %02d:%02d:%02d.%03d", h, m, s,
		 ms );
#endif
	ds = MSECS_PER_DAY;		// make this invalid
	return FALSE;
    }
    ds = (h*SECS_PER_HOUR + m*SECS_PER_MIN + s)*1000 + ms;
    return TRUE;
}

/*!
    Returns a QTime object containing a time \a nsecs seconds later
    than the time of this object (or earlier if \a nsecs is negative).

    Note that the time will wrap if it passes midnight.

    Example:
    \code
    QTime n( 14, 0, 0 );                // n == 14:00:00
    QTime t;
    t = n.addSecs( 70 );                // t == 14:01:10
    t = n.addSecs( -70 );               // t == 13:58:50
    t = n.addSecs( 10*60*60 + 5 );      // t == 00:00:05
    t = n.addSecs( -15*60*60 );         // t == 23:00:00
    \endcode

    \sa addMSecs(), secsTo(), QDateTime::addSecs()
*/

QTime QTime::addSecs( int nsecs ) const
{
    return addMSecs( nsecs * 1000 );
}

/*!
    Returns the number of seconds from this time to \a t (which is
    negative if \a t is earlier than this time).

    Because QTime measures time within a day and there are 86400
    seconds in a day, the result is always between -86400 and 86400.

    \sa addSecs() QDateTime::secsTo()
*/

int QTime::secsTo( const QTime &t ) const
{
    return ((int)t.ds - (int)ds)/1000;
}

/*!
    Returns a QTime object containing a time \a ms milliseconds later
    than the time of this object (or earlier if \a ms is negative).

    Note that the time will wrap if it passes midnight. See addSecs()
    for an example.

    \sa addSecs(), msecsTo()
*/

QTime QTime::addMSecs( int ms ) const
{
    QTime t;
    if ( ms < 0 ) {
	// % not well-defined for -ve, but / is.
	int negdays = (MSECS_PER_DAY-ms) / MSECS_PER_DAY;
	t.ds = ((int)ds + ms + negdays*MSECS_PER_DAY)
		% MSECS_PER_DAY;
    } else {
	t.ds = ((int)ds + ms) % MSECS_PER_DAY;
    }
    return t;
}

/*!
    Returns the number of milliseconds from this time to \a t (which
    is negative if \a t is earlier than this time).

    Because QTime measures time within a day and there are 86400
    seconds in a day, the result is always between -86400000 and
    86400000 msec.

    \sa secsTo()
*/

int QTime::msecsTo( const QTime &t ) const
{
    return (int)t.ds - (int)ds;
}


/*!
    \fn bool QTime::operator==( const QTime &t ) const

    Returns TRUE if this time is equal to \a t; otherwise returns FALSE.
*/

/*!
    \fn bool QTime::operator!=( const QTime &t ) const

    Returns TRUE if this time is different from \a t; otherwise returns FALSE.
*/

/*!
    \fn bool QTime::operator<( const QTime &t ) const

    Returns TRUE if this time is earlier than \a t; otherwise returns FALSE.
*/

/*!
    \fn bool QTime::operator<=( const QTime &t ) const

    Returns TRUE if this time is earlier than or equal to \a t;
    otherwise returns FALSE.
*/

/*!
    \fn bool QTime::operator>( const QTime &t ) const

    Returns TRUE if this time is later than \a t; otherwise returns FALSE.
*/

/*!
    \fn bool QTime::operator>=( const QTime &t ) const

    Returns TRUE if this time is later than or equal to \a t;
    otherwise returns FALSE.
*/



/*!
    \overload

    Returns the current time as reported by the system clock.

    Note that the accuracy depends on the accuracy of the underlying
    operating system; not all systems provide 1-millisecond accuracy.
*/

QTime QTime::currentTime()
{
    return currentTime( Qt::LocalTime );
}

/*!
  Returns the current time as reported by the system clock, for the
  TimeSpec \a ts. The default TimeSpec is LocalTime.

  Note that the accuracy depends on the accuracy of the underlying
  operating system; not all systems provide 1-millisecond accuracy.

  \sa Qt::TimeSpec
*/
QTime QTime::currentTime( Qt::TimeSpec ts )
{
    QTime t;
    currentTime( &t, ts );
    return t;
}

#ifndef QT_NO_DATESTRING
/*!
    Returns the representation \a s as a QTime using the format \a f,
    or an invalid time if this is not possible.

    \warning Note that \c Qt::LocalDate cannot be used here.
*/
QTime QTime::fromString( const QString& s, Qt::DateFormat f )
{
    if ( ( s.isEmpty() ) || ( f == Qt::LocalDate ) ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QTime::fromString: Parameter out of range" );
#endif
	QTime t;
	t.ds = MSECS_PER_DAY;
	return t;
    }

    int hour( s.mid( 0, 2 ).toInt() );
    int minute( s.mid( 3, 2 ).toInt() );
    int second( s.mid( 6, 2 ).toInt() );
    int msec( s.mid( 9, 3 ).toInt() );
    return QTime( hour, minute, second, msec );
}
#endif

/*!
  \internal
  \obsolete

  Fetches the current time and returns TRUE if the time is within one
  minute after midnight, otherwise FALSE. The return value is used by
  QDateTime::currentDateTime() to ensure that the date there is correct.
*/

bool QTime::currentTime( QTime *ct )
{
    return currentTime( ct, Qt::LocalTime );
}


/*!
  \internal

  Fetches the current time, for the TimeSpec \a ts, and returns TRUE
  if the time is within one minute after midnight, otherwise FALSE. The
  return value is used by QDateTime::currentDateTime() to ensure that
  the date there is correct. The default TimeSpec is LocalTime.

  \sa Qt::TimeSpec
*/
bool QTime::currentTime( QTime *ct, Qt::TimeSpec ts )
{
    if ( !ct ) {
#if defined(QT_CHECK_NULL)
	qWarning( "QTime::currentTime(QTime *): Null pointer not allowed" );
#endif
	return FALSE;
    }

#if defined(Q_OS_WIN32)
    SYSTEMTIME t;
    if ( ts == Qt::LocalTime ) {
	GetLocalTime( &t );
    } else {
	GetSystemTime( &t );
    }
    ct->ds = (uint)( MSECS_PER_HOUR*t.wHour + MSECS_PER_MIN*t.wMinute +
		     1000*t.wSecond + t.wMilliseconds );
#elif defined(Q_OS_UNIX)
    // posix compliant system
    struct timeval tv;
    gettimeofday( &tv, 0 );
    time_t ltime = tv.tv_sec;
    tm *t;

#  if defined(QT_THREAD_SUPPORT) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
    // use the reentrant versions of localtime() and gmtime() where available
    tm res;
    if ( ts == Qt::LocalTime )
	t = localtime_r( &ltime, &res );
    else
	t = gmtime_r( &ltime, &res );
#  else
    if ( ts == Qt::LocalTime )
	t = localtime( &ltime );
    else
	t = gmtime( &ltime );
#  endif // QT_THREAD_SUPPORT && _POSIX_THREAD_SAFE_FUNCTIONS

    ct->ds = (uint)( MSECS_PER_HOUR * t->tm_hour + MSECS_PER_MIN * t->tm_min +
		     1000 * t->tm_sec + tv.tv_usec / 1000 );
#else
    time_t ltime; // no millisecond resolution
    ::time( &ltime );
    tm *t;
    if ( ts == Qt::LocalTime )
	localtime( &ltime );
    else
	gmtime( &ltime );
    ct->ds = (uint) ( MSECS_PER_HOUR * t->tm_hour + MSECS_PER_MIN * t->tm_min +
		      1000 * t->tm_sec );
#endif
    // 00:00.00 to 00:00.59.999 is considered as "midnight or right after"
    return ct->ds < (uint) MSECS_PER_MIN;
}

/*!
    \overload

    Returns TRUE if the specified time is valid; otherwise returns
    FALSE.

    The time is valid if \a h is in the range 0..23, \a m and \a s are
    in the range 0..59, and \a ms is in the range 0..999.

    Example:
    \code
    QTime::isValid(21, 10, 30); // returns TRUE
    QTime::isValid(22, 5,  62); // returns FALSE
    \endcode
*/

bool QTime::isValid( int h, int m, int s, int ms )
{
    return (uint)h < 24 && (uint)m < 60 && (uint)s < 60 && (uint)ms < 1000;
}


/*!
    Sets this time to the current time. This is practical for timing:

    \code
    QTime t;
    t.start();
    some_lengthy_task();
    qDebug( "Time elapsed: %d ms", t.elapsed() );
    \endcode

    \sa restart(), elapsed(), currentTime()
*/

void QTime::start()
{
    *this = currentTime();
}

/*!
    Sets this time to the current time and returns the number of
    milliseconds that have elapsed since the last time start() or
    restart() was called.

    This function is guaranteed to be atomic and is thus very handy
    for repeated measurements. Call start() to start the first
    measurement and then restart() for each later measurement.

    Note that the counter wraps to zero 24 hours after the last call
    to start() or restart().

    \warning If the system's clock setting has been changed since the
    last time start() or restart() was called, the result is
    undefined. This can happen when daylight savings time is turned on
    or off.

    \sa start(), elapsed(), currentTime()
*/

int QTime::restart()
{
    QTime t = currentTime();
    int n = msecsTo( t );
    if ( n < 0 )				// passed midnight
	n += 86400*1000;
    *this = t;
    return n;
}

/*!
    Returns the number of milliseconds that have elapsed since the
    last time start() or restart() was called.

    Note that the counter wraps to zero 24 hours after the last call
    to start() or restart.

    Note that the accuracy depends on the accuracy of the underlying
    operating system; not all systems provide 1-millisecond accuracy.

    \warning If the system's clock setting has been changed since the
    last time start() or restart() was called, the result is
    undefined. This can happen when daylight savings time is turned on
    or off.

    \sa start(), restart()
*/

int QTime::elapsed() const
{
    int n = msecsTo( currentTime() );
    if ( n < 0 )				// passed midnight
	n += 86400*1000;
    return n;
}


/*****************************************************************************
  QDateTime member functions
 *****************************************************************************/

/*!
    \class QDateTime qdatetime.h
    \reentrant
    \brief The QDateTime class provides date and time functions.

    \ingroup time
    \mainclass

    A QDateTime object contains a calendar date and a clock time (a
    "datetime"). It is a combination of the QDate and QTime classes.
    It can read the current datetime from the system clock. It
    provides functions for comparing datetimes and for manipulating a
    datetime by adding a number of seconds, days, months or years.

    A QDateTime object is typically created either by giving a date
    and time explicitly in the constructor, or by using the static
    function currentDateTime(), which returns a QDateTime object set
    to the system clock's time. The date and time can be changed with
    setDate() and setTime(). A datetime can also be set using the
    setTime_t() function, which takes a POSIX-standard "number of
    seconds since 00:00:00 on January 1, 1970" value. The fromString()
    function returns a QDateTime given a string and a date format
    which is used to interpret the date within the string.

    The date() and time() functions provide access to the date and
    time parts of the datetime. The same information is provided in
    textual format by the toString() function.

    QDateTime provides a full set of operators to compare two
    QDateTime objects where smaller means earlier and larger means
    later.

    You can increment (or decrement) a datetime by a given number of
    seconds using addSecs() or days using addDays(). Similarly you can
    use addMonths() and addYears(). The daysTo() function returns the
    number of days between two datetimes, and secsTo() returns the
    number of seconds between two datetimes.

    The range of a datetime object is constrained to the ranges of the
    QDate and QTime objects which it embodies.

    \sa QDate QTime QDateTimeEdit
*/


/*!
    \fn QDateTime::QDateTime()

    Constructs a null datetime (i.e. null date and null time). A null
    datetime is invalid, since the date is invalid.

    \sa isValid()
*/


/*!
    Constructs a datetime with date \a date and null (but valid) time
    (00:00:00.000).
*/

QDateTime::QDateTime( const QDate &date )
    : d(date)
{
}

/*!
    Constructs a datetime with date \a date and time \a time.
*/

QDateTime::QDateTime( const QDate &date, const QTime &time )
    : d(date), t(time)
{
}


/*!
    \fn bool QDateTime::isNull() const

    Returns TRUE if both the date and the time are null; otherwise
    returns FALSE. A null datetime is invalid.

    \sa QDate::isNull(), QTime::isNull()
*/

/*!
    \fn bool QDateTime::isValid() const

    Returns TRUE if both the date and the time are valid; otherwise
    returns FALSE.

    \sa QDate::isValid(), QTime::isValid()
*/

/*!
    \fn QDate QDateTime::date() const

    Returns the date part of the datetime.

    \sa setDate(), time()
*/

/*!
    \fn QTime QDateTime::time() const

    Returns the time part of the datetime.

    \sa setTime(), date()
*/

/*!
    \fn void QDateTime::setDate( const QDate &date )

    Sets the date part of this datetime to \a date.

    \sa date(), setTime()
*/

/*!
    \fn void QDateTime::setTime( const QTime &time )

    Sets the time part of this datetime to \a time.

    \sa time(), setDate()
*/


/*!
    Returns the datetime as the number of seconds that have passed
    since 1970-01-01T00:00:00, Coordinated Universal Time (UTC).

    On systems that do not support timezones, this function will
    behave as if local time were UTC.

    \sa setTime_t()
*/

uint QDateTime::toTime_t() const
{
    tm brokenDown;
    brokenDown.tm_sec = t.second();
    brokenDown.tm_min = t.minute();
    brokenDown.tm_hour = t.hour();
    brokenDown.tm_mday = d.day();
    brokenDown.tm_mon = d.month() - 1;
    brokenDown.tm_year = d.year() - 1900;
    brokenDown.tm_isdst = -1;
    int secsSince1Jan1970UTC = (int) mktime( &brokenDown );
    if ( secsSince1Jan1970UTC < -1 )
	secsSince1Jan1970UTC = -1;
    return (uint) secsSince1Jan1970UTC;
}

/*!
    \overload

    Convenience function that sets the date and time to local time
    based on the given UTC time.
*/

void QDateTime::setTime_t( uint secsSince1Jan1970UTC )
{
    setTime_t( secsSince1Jan1970UTC, Qt::LocalTime );
}

/*!
    Sets the date and time to \a ts time (\c Qt::LocalTime or \c
    Qt::UTC) given the number of seconds that have passed since
    1970-01-01T00:00:00, Coordinated Universal Time (UTC). On systems
    that do not support timezones this function will behave as if
    local time were UTC.

    On Windows, only a subset of \a secsSince1Jan1970UTC values are
    supported, as Windows starts counting from 1980.

    \sa toTime_t()
*/
void QDateTime::setTime_t( uint secsSince1Jan1970UTC, Qt::TimeSpec ts )
{
    time_t tmp = (time_t) secsSince1Jan1970UTC;
    tm *brokenDown = 0;

#if defined(Q_OS_UNIX) && defined(QT_THREAD_SUPPORT) && defined(_POSIX_THREAD_SAFE_FUNCTIONS)
    // posix compliant system
    // use the reentrant versions of localtime() and gmtime() where available
    tm res;
    if ( ts == Qt::LocalTime )
	brokenDown = localtime_r( &tmp, &res );
    if ( !brokenDown ) {
	brokenDown = gmtime_r( &tmp, &res );
	if ( !brokenDown ) {
	    d.jd = QDate::gregorianToJulian( 1970, 1, 1 );
	    t.ds = 0;
	    return;
	}
    }
#else
    if ( ts == Qt::LocalTime )
	brokenDown = localtime( &tmp );
    if ( !brokenDown ) {
	brokenDown = gmtime( &tmp );
	if ( !brokenDown ) {
	    d.jd = QDate::gregorianToJulian( 1970, 1, 1 );
	    t.ds = 0;
	    return;
	}
    }
#endif

    d.jd = QDate::gregorianToJulian( brokenDown->tm_year + 1900,
				     brokenDown->tm_mon + 1,
				     brokenDown->tm_mday );
    t.ds = MSECS_PER_HOUR * brokenDown->tm_hour +
	   MSECS_PER_MIN * brokenDown->tm_min +
	   1000 * brokenDown->tm_sec;
}
#ifndef QT_NO_DATESTRING
#ifndef QT_NO_SPRINTF
/*!
    \overload

    Returns the datetime as a string. The \a f parameter determines
    the format of the string.

    If \a f is \c Qt::TextDate, the string format is "Wed May 20
    03:40:13 1998" (using QDate::shortDayName(), QDate::shortMonthName(),
    and QTime::toString() to generate the string, so the day and month
    names will have localized names).

    If \a f is \c Qt::ISODate, the string format corresponds to the
    ISO 8601 extended specification for representations of dates and
    times, which is YYYY-MM-DDTHH:MM:SS.

    If \a f is \c Qt::LocalDate, the string format depends on the
    locale settings of the system.

    If the format \a f is invalid or the datetime is invalid, toString()
    returns a null string.

    \sa QDate::toString() QTime::toString()
*/

QString QDateTime::toString( Qt::DateFormat f ) const
{
    if ( !isValid() )
	return QString::null;

    if ( f == Qt::ISODate ) {
	return d.toString( Qt::ISODate ) + "T" + t.toString( Qt::ISODate );
    }
#ifndef QT_NO_TEXTDATE
    else if ( f == Qt::TextDate ) {
#ifndef Q_WS_WIN
	QString buf = d.shortDayName( d.dayOfWeek() );
	buf += ' ';
	buf += d.shortMonthName( d.month() );
	buf += ' ';
	buf += QString().setNum( d.day() );
	buf += ' ';
#else
	QString buf;
	QString winstr;
	QT_WA( {
	    TCHAR out[255];
	    GetLocaleInfo( LOCALE_USER_DEFAULT, LOCALE_ILDATE, out, 255 );
	    winstr = QString::fromUcs2( (ushort*)out );
	} , {
	    char out[255];
	    GetLocaleInfoA( LOCALE_USER_DEFAULT, LOCALE_ILDATE, (char*)&out, 255 );
	    winstr = QString::fromLocal8Bit( out );
	} );
	switch ( winstr.toInt() ) {
	case 1:
	    buf = d.shortDayName( d.dayOfWeek() ) + " " + QString().setNum( d.day() ) + ". " + d.shortMonthName( d.month() ) + " ";
	    break;
	default:
	    buf = d.shortDayName( d.dayOfWeek() ) + " " + d.shortMonthName( d.month() ) + " " + QString().setNum( d.day() ) + " ";
	    break;
	}
#endif
	buf += t.toString();
	buf += ' ';
	buf += QString().setNum( d.year() );
	return buf;
    }
#endif
    else if ( f == Qt::LocalDate ) {
	return d.toString( Qt::LocalDate ) + " " + t.toString( Qt::LocalDate );
    }
    return QString::null;
}
#endif

/*!
    Returns the datetime as a string. The \a format parameter
    determines the format of the result string.

    These expressions may be used for the date:

    \table
    \header \i Expression \i Output
    \row \i d \i the day as number without a leading zero (1-31)
    \row \i dd \i the day as number with a leading zero (01-31)
    \row \i ddd
	    \i the abbreviated localized day name (e.g. 'Mon'..'Sun').
	    Uses QDate::shortDayName().
    \row \i dddd
	    \i the long localized day name (e.g. 'Monday'..'Sunday').
	    Uses QDate::longDayName().
    \row \i M \i the month as number without a leading zero (1-12)
    \row \i MM \i the month as number with a leading zero (01-12)
    \row \i MMM
	    \i the abbreviated localized month name (e.g. 'Jan'..'Dec').
	    Uses QDate::shortMonthName().
    \row \i MMMM
	    \i the long localized month name (e.g. 'January'..'December').
	    Uses QDate::longMonthName().
    \row \i yy \i the year as two digit number (00-99)
    \row \i yyyy \i the year as four digit number (1752-8000)
    \endtable

    These expressions may be used for the time:

    \table
    \header \i Expression \i Output
    \row \i h
	    \i the hour without a leading zero (0..23 or 1..12 if AM/PM display)
    \row \i hh
	    \i the hour with a leading zero (00..23 or 01..12 if AM/PM display)
    \row \i m \i the minute without a leading zero (0..59)
    \row \i mm \i the minute with a leading zero (00..59)
    \row \i s \i the second whithout a leading zero (0..59)
    \row \i ss \i the second whith a leading zero (00..59)
    \row \i z \i the milliseconds without leading zeroes (0..999)
    \row \i zzz \i the milliseconds with leading zeroes (000..999)
    \row \i AP
	    \i use AM/PM display. \e AP will be replaced by either "AM" or "PM".
    \row \i ap
	    \i use am/pm display. \e ap will be replaced by either "am" or "pm".
    \endtable

    All other input characters will be ignored.

    Example format strings (assumed that the QDateTime is
    21<small><sup>st</sup></small> May 2001 14:13:09)

    \table
    \header \i Format \i Result
    \row \i dd.MM.yyyy	    \i11 21.05.2001
    \row \i ddd MMMM d yy   \i11 Tue May 21 01
    \row \i hh:mm:ss.zzz    \i11 14:13:09.042
    \row \i h:m:s ap	    \i11 2:13:9 pm
    \endtable

    If the datetime is an invalid datetime, then QString::null will be returned.

    \sa QDate::toString() QTime::toString()
*/
QString QDateTime::toString( const QString& format ) const
{
    return fmtDateTime( format, &t, &d );
}
#endif //QT_NO_DATESTRING

/*!
    Returns a QDateTime object containing a datetime \a ndays days
    later than the datetime of this object (or earlier if \a ndays is
    negative).

    \sa daysTo(), addMonths(), addYears(), addSecs()
*/

QDateTime QDateTime::addDays( int ndays ) const
{
    return QDateTime( d.addDays(ndays), t );
}

/*!
    Returns a QDateTime object containing a datetime \a nmonths months
    later than the datetime of this object (or earlier if \a nmonths
    is negative).

    \sa daysTo(), addDays(), addYears(), addSecs()
*/

QDateTime QDateTime::addMonths( int nmonths ) const
{
    return QDateTime( d.addMonths(nmonths), t );
}

/*!
    Returns a QDateTime object containing a datetime \a nyears years
    later than the datetime of this object (or earlier if \a nyears is
    negative).

    \sa daysTo(), addDays(), addMonths(), addSecs()
*/

QDateTime QDateTime::addYears( int nyears ) const
{
    return QDateTime( d.addYears(nyears), t );
}

/*!
    Returns a QDateTime object containing a datetime \a nsecs seconds
    later than the datetime of this object (or earlier if \a nsecs is
    negative).

    \sa secsTo(), addDays(), addMonths(), addYears()
*/

QDateTime QDateTime::addSecs( int nsecs ) const
{
    uint dd = d.jd;
    int  tt = t.ds;
    int  sign = 1;
    if ( nsecs < 0 ) {
	nsecs = -nsecs;
	sign = -1;
    }
    if ( nsecs >= (int)SECS_PER_DAY ) {
	dd += sign*(nsecs/SECS_PER_DAY);
	nsecs %= SECS_PER_DAY;
    }
    tt += sign*nsecs*1000;
    if ( tt < 0 ) {
	tt = MSECS_PER_DAY - tt - 1;
	dd -= tt / MSECS_PER_DAY;
	tt = tt % MSECS_PER_DAY;
	tt = MSECS_PER_DAY - tt - 1;
    } else if ( tt >= (int)MSECS_PER_DAY ) {
	dd += ( tt / MSECS_PER_DAY );
	tt = tt % MSECS_PER_DAY;
    }
    QDateTime ret;
    ret.t.ds = tt;
    ret.d.jd = dd;
    return ret;
}

/*!
    Returns the number of days from this datetime to \a dt (which is
    negative if \a dt is earlier than this datetime).

    \sa addDays(), secsTo()
*/

int QDateTime::daysTo( const QDateTime &dt ) const
{
    return d.daysTo( dt.d );
}

/*!
    Returns the number of seconds from this datetime to \a dt (which
    is negative if \a dt is earlier than this datetime).

    Example:
    \code
    QDateTime dt = QDateTime::currentDateTime();
    QDateTime xmas( QDate(dt.date().year(),12,24), QTime(17,00) );
    qDebug( "There are %d seconds to Christmas", dt.secsTo(xmas) );
    \endcode

    \sa addSecs(), daysTo(), QTime::secsTo()
*/

int QDateTime::secsTo( const QDateTime &dt ) const
{
    return t.secsTo(dt.t) + d.daysTo(dt.d)*SECS_PER_DAY;
}


/*!
    Returns TRUE if this datetime is equal to \a dt; otherwise returns FALSE.

    \sa operator!=()
*/

bool QDateTime::operator==( const QDateTime &dt ) const
{
    return  t == dt.t && d == dt.d;
}

/*!
    Returns TRUE if this datetime is different from \a dt; otherwise
    returns FALSE.

    \sa operator==()
*/

bool QDateTime::operator!=( const QDateTime &dt ) const
{
    return  t != dt.t || d != dt.d;
}

/*!
    Returns TRUE if this datetime is earlier than \a dt; otherwise
    returns FALSE.
*/

bool QDateTime::operator<( const QDateTime &dt ) const
{
    if ( d < dt.d )
	return TRUE;
    return d == dt.d ? t < dt.t : FALSE;
}

/*!
    Returns TRUE if this datetime is earlier than or equal to \a dt;
    otherwise returns FALSE.
*/

bool QDateTime::operator<=( const QDateTime &dt ) const
{
    if ( d < dt.d )
	return TRUE;
    return d == dt.d ? t <= dt.t : FALSE;
}

/*!
    Returns TRUE if this datetime is later than \a dt; otherwise
    returns FALSE.
*/

bool QDateTime::operator>( const QDateTime &dt ) const
{
    if ( d > dt.d )
	return TRUE;
    return d == dt.d ? t > dt.t : FALSE;
}

/*!
    Returns TRUE if this datetime is later than or equal to \a dt;
    otherwise returns FALSE.
*/

bool QDateTime::operator>=( const QDateTime &dt ) const
{
    if ( d > dt.d )
	return TRUE;
    return d == dt.d ? t >= dt.t : FALSE;
}

/*!
    \overload

    Returns the current datetime, as reported by the system clock.

    \sa QDate::currentDate(), QTime::currentTime()
*/

QDateTime QDateTime::currentDateTime()
{
    return currentDateTime( Qt::LocalTime );
}

/*!
  Returns the current datetime, as reported by the system clock, for the
  TimeSpec \a ts. The default TimeSpec is LocalTime.

  \sa QDate::currentDate(), QTime::currentTime(), Qt::TimeSpec
*/

QDateTime QDateTime::currentDateTime( Qt::TimeSpec ts )
{
    QDateTime dt;
    QTime t;
    dt.setDate( QDate::currentDate(ts) );
    if ( QTime::currentTime(&t, ts) )         // midnight or right after?
	dt.setDate( QDate::currentDate(ts) ); // fetch date again
    dt.setTime( t );
    return dt;
}

#ifndef QT_NO_DATESTRING
/*!
    Returns the QDateTime represented by the string \a s, using the
    format \a f, or an invalid datetime if this is not possible.

    Note for \c Qt::TextDate: It is recommended that you use the
    English short month names (e.g. "Jan"). Although localized month
    names can also be used, they depend on the user's locale settings.

    \warning Note that \c Qt::LocalDate cannot be used here.
*/
QDateTime QDateTime::fromString( const QString& s, Qt::DateFormat f )
{
    if ( ( s.isEmpty() ) || ( f == Qt::LocalDate ) ) {
#if defined(QT_CHECK_RANGE)
	qWarning( "QDateTime::fromString: Parameter out of range" );
#endif
	QDateTime dt;
	dt.d.jd = 0;
	return dt;
    }
    if ( f == Qt::ISODate ) {
	return QDateTime( QDate::fromString( s.mid(0,10), Qt::ISODate ),
			  QTime::fromString( s.mid(11), Qt::ISODate ) );
    }
#if !defined(QT_NO_REGEXP) && !defined(QT_NO_TEXTDATE)
    else if ( f == Qt::TextDate ) {
	QString monthName( s.mid( 4, 3 ) );
	int month = -1;
	// Assume that English monthnames are the default
	for ( int i = 0; i < 12; ++i ) {
	    if ( monthName == qt_shortMonthNames[i] ) {
		month = i + 1;
		break;
	    }
	}
	// If English names can't be found, search the localized ones
	if ( month == -1 ) {
	    for ( int i = 1; i <= 12; ++i ) {
		if ( monthName == QDate::shortMonthName( i ) ) {
		    month = i;
		    break;
		}
	    }
	}
#if defined(QT_CHECK_RANGE)
	if ( month < 1 || month > 12 ) {
	    qWarning( "QDateTime::fromString: Parameter out of range" );
	    QDateTime dt;
	    dt.d.jd = 0;
	    return dt;
	}
#endif
	int day = s.mid( 8, 2 ).simplifyWhiteSpace().toInt();
	int year = s.right( 4 ).toInt();
	QDate date( year, month, day );
	QTime time;
	int hour, minute, second;
	int pivot = s.find( QRegExp(QString::fromLatin1("[0-9][0-9]:[0-9][0-9]:[0-9][0-9]")) );
	if ( pivot != -1 ) {
	    hour = s.mid( pivot, 2 ).toInt();
	    minute = s.mid( pivot+3, 2 ).toInt();
	    second = s.mid( pivot+6, 2 ).toInt();
	    time.setHMS( hour, minute, second );
	}
	return QDateTime( date, time );
    }
#endif //QT_NO_REGEXP
    return QDateTime();
}
#endif //QT_NO_DATESTRING


/*****************************************************************************
  Date/time stream functions
 *****************************************************************************/

#ifndef QT_NO_DATASTREAM
/*!
    \relates QDate

    Writes the date, \a d, to the data stream, \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator<<( QDataStream &s, const QDate &d )
{
    return s << (Q_UINT32)(d.jd);
}

/*!
    \relates QDate

    Reads a date from the stream \a s into \a d.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator>>( QDataStream &s, QDate &d )
{
    Q_UINT32 jd;
    s >> jd;
    d.jd = jd;
    return s;
}

/*!
    \relates QTime

    Writes time \a t to the stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator<<( QDataStream &s, const QTime &t )
{
    return s << (Q_UINT32)(t.ds);
}

/*!
    \relates QTime

    Reads a time from the stream \a s into \a t.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator>>( QDataStream &s, QTime &t )
{
    Q_UINT32 ds;
    s >> ds;
    t.ds = ds;
    return s;
}

/*!
    \relates QDateTime

    Writes the datetime \a dt to the stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator<<( QDataStream &s, const QDateTime &dt )
{
    return s << dt.d << dt.t;
}

/*!
    \relates QDateTime

    Reads a datetime from the stream \a s into \a dt.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator>>( QDataStream &s, QDateTime &dt )
{
    s >> dt.d >> dt.t;
    return s;
}
#endif //QT_NO_DATASTREAM
