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Subsections

- Temporal Constants
- Temporal Operators
  - Temporal Negation
  - Temporal Addition
  - Temporal Subtraction
  - Temporal Multiplication
  - Temporal Division
  - Temporal Relationals

#
Temporal Types

Bro supports types representing absolute and relative times with the `time` and `interval` types, respectively.

##
Temporal Constants

There is currently no way to specify an absolute time as a constant (though see the `current_time` and `network_time` functions in § ). You can specify `interval` constants, however, by appending a time unit after a numeric constant. For example,

        3.5 min

denotes 210 seconds. The different time units are `usec`, `sec`, `min`, `hr`, and `day`, representing microseconds, seconds, minutes, hours, and days, respectively. The whitespace between the numeric constant and the unit is optional, and the letter ``s'' may be added to pluralize the unit (this has no semantic effect). So the above example could also be written:

        3.5mins

or

        150 secs

##
Temporal Operators

You can apply arithmetic and relational operators to temporal values, as follows.

###
Temporal Negation

The unary `-` operator can be applied to an `interval` value to yield another `interval` value. For example,

        - 12 hr

represents ``twelve hours in the past.''

###
Temporal Addition

Adding two `interval` values yields another `interval` value. For example,

        5 sec + 2 min

yields 125 seconds. Adding a `time` value to an `interval` yields another `time` value.

###
Temporal Subtraction

Subtracting a `time` value from another `time` value yields an `interval` value, as does subtracting an `interval` value from another `interval`, while subtracting an `interval` from a `time` yields a `time`.

###
Temporal Multiplication

You can multiply an `interval` value by a numeric value to yield another `interval` value. For example,

       5 min * 6.5

yields 1,950 seconds. `time` values cannot be scaled by multiplication or division.

###
Temporal Division

You can also divide an `interval` value by a numeric value to yield another `interval` value. For example,

       5 min / 2

yields 150 seconds. Furthermore, you can divide one `interval` value by another to yield a `double`. For example,

       5 min / 30 sec

yields 10.

###
Temporal Relationals

You may compare two `time` values or two `interval` values for equality, and also for ordering, where times or intervals further in the future are considered larger than times or intervals nearer in the future, or in the past.

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