[Unit]
Description=write alarm time to rtc
Before=ntp.service vdr.service
ConditionPathExists=/sys/class/rtc

[Service]
Type=oneshot
RemainAfterExit=true
ExecStart=/bin/true
ExecStop=/bin/bash -c 'TIME_TO_SET=$(</var/cache/vdr/acpiwakeup.time) ; /usr/sbin/rtcwake -m no -a -t $TIME_TO_SET'

[Install]
RequiredBy=vdr.service