Type a cron expression to see what it means in plain English - or build one from the dropdowns. Either way you get the next five run times, so you know the schedule does what you think before it goes in a crontab.
Next 5 runs (your local time):
The && curl tail is a heartbeat ping - it tells a monitor the job ran, so you find out when it silently stops. Delete it if you just want the schedule.
Five fields, space-separated, left to right: minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-7, where both 0 and 7 are Sunday). Each field takes a number, a range (1-5), a list (0,30), a step (*/5), or * for "every". When both day-of-month and day-of-week are restricted, standard cron runs when either matches - the classic surprise in expressions like 0 0 13 * 5, which fires on the 13th and every Friday.
Cron is a scheduler, not a supervisor. It will start your job on time forever - and say nothing when the job exits non-zero, hangs, or stops producing backups because a path changed. Every team eventually finds a cron job that has been failing for weeks. The fix is the one-line heartbeat pattern shown above: the job pings a URL on success, and a monitor alerts when the ping stops arriving - which catches every failure mode, including the ones where cron itself never ran. The heartbeat guide covers grace periods and exit-code pitfalls.
A schedule is a promise; a heartbeat checks it's kept. AlertKick heartbeat monitors are free: your job pings a URL on success, and you get alerted the moment a ping goes missing - before anyone needs the backup that isn't there.
Monitor my cron jobs - free