Systemd Timers

For systemd-based scheduling, add the ping to your service unit using ExecStartPost:

/etc/systemd/system/backup.service
[Unit]
Description=Database Backup

[Service]
Type=oneshot
ExecStart=/usr/local/bin/backup.sh
ExecStartPost=/usr/bin/curl -fsS https://watchcron.com/ping/your-uuid

ExecStartPost only runs when ExecStart exits successfully (code 0), so the ping is only sent on success.

/etc/systemd/system/backup.timer
[Unit]
Description=Run backup every 6 hours

[Timer]
OnCalendar=*-*-* 00/6:00:00
Persistent=true

[Install]
WantedBy=timers.target
Persistent=true ensures the timer fires after a missed run (e.g., if the server was rebooted). Enable the timer with systemctl enable --now backup.timer.