Mastering Cron Syntax
If you manage servers or deploy backend code, you inevitably encounter Cron. It is the standard utility for scheduling tasks on Linux systems.
However, the syntax (`* * * * *`) is notoriously hard to memorize. A single mistake can mean your database backup runs every minute instead of every day.
The 5 Fields Explained
*
Minute
0 - 59
*
Hour
0 - 23
*
Day (Month)
1 - 31
*
Month
1 - 12
*
Day (Week)
0 - 6
Special Characters
- * (Asterisk): "Every". Run at every unit of time.
- , (Comma): "List". `1,3,5` means run on 1st, 3rd, and 5th.
- - (Hyphen): "Range". `1-5` means run on 1, 2, 3, 4, and 5.
- / (Slash): "Step". `*/15` means run every 15 units.