coreos – Systemd: how to keep the timer active after restarting?

I need to configure the daily reboot of the CoreOS machine. So I have /etc/systemd/system/reboot.service:

[Unit]



Description = daily restart

[Service]
Type = oneshot
ExecStart = / usr / bin / sh -c & # 39; restart & # 39;

…Y /etc/systemd/system/reboot.timer:

[Unit]



Description = daily restart

[Timer]
OnCalendar = * - * - * 21:20:00

If I activate the timer by sudo systemctl start reboot.timer, I see it in the list:

core @ node-011 ~ $ sudo systemctl list-timers --all | grep restart
Fri 2019-03-22 21:20:00 UTC 12 h left n / a n / a reboot.timer reboot.service
core @ node-011 ~ $ 

But after restarting, this timer went off (not in the list).

How to configure it persistent?