[Unit]
Description=Wake Alarm RTC arming, every 15 min all day and on boot
Documentation=https://github.com/kuhyx/wake-alarm

[Timer]
# Every 15 min, all day: a PC hibernated at 16:00 the day before a stick day
# must still have been armed. There is no sleep.target in the *user*
# manager, so resume is covered by the calendar itself: a calendar timer
# that elapsed while the system slept "will catch up" once it is resumed
# (systemd.timer(5)), and with a 15-min cadence every sleep longer than a
# quarter hour re-arms (or disarms) right after resume.
OnCalendar=*-*-* *:00/15:00
# Fresh boot (a CMOS alarm survives a poweroff, but re-check it anyway).
OnBootSec=2min
AccuracySec=1min

[Install]
WantedBy=timers.target