How to read a cron expression
Paste or type an expression into the box. The parser checks each of the five fields, writes the schedule out in plain English, and lists the next eight times it would fire in your local time zone. The preset buttons load common schedules to start from. Shortcuts such as @hourly, @daily, @weekly, @monthly and @yearly are expanded to their five-field form.
Cron syntax quick reference
| Symbol | Meaning | Example | Reads as |
|---|---|---|---|
* | Every value | * * * * * | Every minute |
, | List | 0 8,12,18 * * * | At 08:00, 12:00 and 18:00 |
- | Range | 0 9 * * 1-5 | At 09:00, Monday to Friday |
/ | Step | */10 * * * * | Every 10 minutes |
| Names | Months and days | 0 0 1 JAN,JUL * | Midnight on 1 January and 1 July |
Common cron schedules
| Expression | Schedule |
|---|---|
*/5 * * * * | Every 5 minutes |
0 * * * * | Every hour, on the hour |
0 */6 * * * | Every 6 hours (00:00, 06:00, 12:00, 18:00) |
0 0 * * * | Every day at midnight |
30 2 * * 0 | Every Sunday at 02:30 |
0 9 * * 1-5 | Weekdays at 09:00 |
0 0 1 * * | First day of every month at midnight |
0 0 1 1 * | Once a year, 1 January at midnight |
For the full syntax, platform differences and the mistakes that cause silent failures, read cron syntax explained. To check a timestamp in a job's log output, use the Unix Timestamp Converter, and to fix file permissions on a script cron cannot execute, use the Chmod Calculator.