[rocqua]

The cron alternative that does something only once is 'at'.

[Ao7bei3s]

The modern at alternative is:

systemd-run --user --on-calendar=23:20 notify-send Example

Or relative with --on-active=60. And you automatically get the normal systemd tooling, e.g. systemctl list-timers.

[merb]

well this works fine for a single host. but if you deal with a cluster or inside a cloud you better use kubernetes for that.