gistfile1.txt

[Unit]
Description=Delayed hibernation trigger
Documentation=https://bbs.archlinux.org/viewtopic.php?pid=1420279#p1420279
Documentation=https://wiki.archlinux.org/index.php/Power_management
Conflicts=hibernate.target hybrid-sleep.target
Before=sleep.target
StopWhenUnneeded=true

[Service]
Type=oneshot
RemainAfterExit=yes
Environment="WAKEALARM=/sys/class/rtc/rtc0/wakealarm"
Environment="SLEEPLENGTH=+30min"
ExecStart=-/usr/bin/sh -c 'echo -n "alarm set for "; date +%%s -d$SLEEPLENGTH | tee $WAKEALARM'
ExecStop=-/usr/bin/sh -c '\
 alarm=$(cat $WAKEALARM); \
 now=$(date +%%s); \
 if [ -z "$alarm" ] || [ "$now" -ge "$alarm" ]; then \
 echo "hibernate triggered"; \
 systemctl hibernate; \
 else \
 echo "normal wakeup"; \
 fi; \
 echo 0 > $WAKEALARM; \
'

[Install]
WantedBy=sleep.target