rtcwake

Enter a system sleep state until specified wakeup time relative to your BIOS clock. More information: https://manned.org/rtcwake.

• Show whether an alarm is set or not:

sudo rtcwake {{[-m|--mode]}} show {{[-v|--verbose]}}

• Suspend to RAM and wakeup after 10 seconds:

sudo rtcwake {{[-m|--mode]}} mem {{[-s|--seconds]}} {{10}}

• Suspend to disk (higher power saving) and wakeup 15 minutes later:

sudo rtcwake {{[-m|--mode]}} disk --date +{{15}}min

• Freeze the system (more efficient than suspend-to-RAM but version 3.9 or newer of the Linux kernel is required) and wakeup at a given date and time:

sudo rtcwake {{[-m|--mode]}} freeze --date {{YYYYMMDDhhmm}}

• Disable a previously set alarm:

sudo rtcwake {{[-m|--mode]}} disable

• Perform a dry run to wakeup the computer at a given time. (Press <Ctrl c> to abort):

sudo rtcwake {{[-m|--mode]}} on --date {{hh:ss}}