A cron expression schedules recurring jobs in five fields. Learn what each field means, decode common expressions like 0 9 * * 1, and build your own free in your browser.
A cron expression like 0 9 * * 1 tells a scheduler to run a job at a specific time — in this case, 9:00 AM every Monday. Cron powers scheduled backups, reports, cleanups, and automations everywhere from servers to CI pipelines. The syntax is compact but cryptic, which is exactly why a generator that shows you what each expression means is so handy.
A standard cron expression has five space-separated fields, read left to right. An asterisk (*) means “every”.
| Position | Field | Allowed values |
|---|---|---|
| 1 | Minute | 0–59 |
| 2 | Hour | 0–23 |
| 3 | Day of month | 1–31 |
| 4 | Month | 1–12 |
| 5 | Day of week | 0–6 (Sun–Sat) |
| Expression | Runs |
|---|---|
* * * * * | Every minute |
0 * * * * | Every hour, on the hour |
0 0 * * * | Every day at midnight |
0 9 * * 1 | 9:00 AM every Monday |
*/15 * * * * | Every 15 minutes |
0 0 1 * * | Midnight on the 1st of each month |
*/n means “every n”. */15 in the minute field runs every 15 minutes.0,30 means at 0 and 30; 1-5 in day-of-week means Monday to Friday.Cron expressions pack a full schedule into five fields — minute, hour, day, month, weekday. Once you know the layout, expressions like 0 9 * * 1 read at a glance. Build and decode them with the ToolsGravity Cron Expression Generator, and always double-check the server timezone.