Cron Expression Generator

Build from the controls, or type an expression and let the page explain it.

1. Choose a Preset such as Weekdays at 09:00 or First day of every month as a starting point. It overwrites the expression box.
2. Alternatively use the selects for Minute, Hour, Day of month, Month and Day of week. Changing any of them rebuilds the Cron expression box.
3. For anything the menus do not offer, type straight into the Cron expression box. The menus only list common choices, so custom values go here.
4. Read the big result: the expression with its plain-English description underneath, then a table of the five fields.
5. Check the Next run table, which lists the next five times in your device time zone with how long until each.
6. Press Copy expression, or Reset to return to the default.

An expression without exactly five fields shows a warning instead of a result.

The presets are Every minute, Every 5 minutes, Every hour, Daily at midnight, Weekdays at 09:00, Every Sunday at midnight, First day of every month and Once a year (1 January). Cron cannot express every second Tuesday or the last day of a month directly, so schedule such a job more often and let the script decide whether to run.

An asterisk matches every value, a comma lists values, a hyphen gives a range and a slash sets a step. Both 0 and 7 mean Sunday. The tool also reads forms such as 1-10/2 and 5/10. It does not understand @daily, @reboot, ?, L, W, #, H, or the six- and seven-field layouts that add seconds or a year.

Some worked readings: */15 * * * * is Every 15 minutes; 30 2 1 * * is At 02:30, on day 1 of the month. When both day fields are restricted, standard cron runs the job if either one matches, and the tool follows that rule, so 0 0 13 * 5 fires on every 13th and on every Friday, not only on Friday the 13th. A value out of range, such as minute 61, is reported by name.

The wording is generated from the fields, so unusual combinations read a little stiffly. Use the run times as the final check.

The five-field format is widely shared, but the details are not, and the wrong assumption usually shows up as a job firing at the wrong hour.

• Linux crontab uses the server local time and supports shortcuts like @daily.
• GitHub Actions evaluates schedules in UTC, so a local 9 a.m. needs converting, and its shortest interval is five minutes.
• Jenkins adds H, which picks a stable minute from a hash of the job name to spread load.
• Quartz, Spring and AWS EventBridge use six or seven fields and the symbols ? and L, so a five-field expression must be adapted.
• Kubernetes CronJob uses the standard five fields and the controller time zone unless timeZone is set.

This page shows run times in your own zone, so translate to the scheduler zone before you rely on them. The preview looks ahead 366 days. A valid but rare schedule, such as 29 February, may therefore show no runs, as does an impossible one like 31 February. The time zone converter helps move a local time to UTC. The Unix timestamp converter turns a logged run time into a readable date, and the date difference calculator counts days between two dates.