Quick Presets
Paste or Type Expression
Visual Builder
Frequently Asked Questions
A cron expression is a string of 5 (or 6) fields separated by spaces that defines a recurring schedule: minute, hour, day-of-month, month, day-of-week.
"*" means every — every minute, every hour, every day, etc. "*/5" in the minutes field means every 5 minutes.
Use "0 0 * * *" — minute 0, hour 0 (midnight), every day, every month, every day of week.
Standard Unix cron uses 5 fields (minute to weekday). AWS EventBridge and some tools add a 6th field for year. Some tools add seconds as the first field.
Use "*/15 * * * *" — this runs at minutes 0, 15, 30, and 45 of every hour.
About this calculator
Pick a quick preset or edit each of the five fields, and see the resulting cron expression with a plain-English description. You can also paste an expression to see it broken down.
Presets include every minute, every 5 and 15 minutes, hourly, daily at midnight and 9 am, weekdays, weekly, monthly and yearly.
How to use it
- Tap a preset or edit the fields.
- Or paste an expression in the manual box.
- Copy the expression.
Syntax
A cron expression has five fields: minute (0-59) hour (0-23) day-of-month (1-31) month (1-12) day-of-week (0-7, Sunday is 0 or 7). * means every value, */15 every 15th, 1-5 a range and 1,15 a list. Examples: 0 9 * * 1-5 is 9:00 on weekdays, */15 * * * * every 15 minutes, 0 0 1 * * midnight on the 1st of each month. If both day-of-month and day-of-week are restricted, standard cron runs when either matches.
Worked example
Common schedules
| * * * * * | Every minute |
| */5 * * * * | Every 5 minutes |
| 0 * * * * | Every hour |
| 0 0 * * * | Every day at midnight |
| 0 9 * * 1-5 | 9:00 AM on weekdays |
| 0 0 1 * * | Midnight on the 1st of each month |
Tips and common mistakes
- Cron uses the server's time zone, usually UTC. Check before scheduling.
- Redirect output (>> log 2>&1) so you can see errors.
- Use absolute paths in cron commands.
- Avoid scheduling many jobs at minute 0.
- Test the command by hand before adding it to cron.
Frequently asked questions
What is a cron expression?
Five fields describing when a scheduled job runs.
What does */5 mean?
Every 5 units, so every 5 minutes in the minute field.
Is Sunday 0 or 7?
Both are accepted in most cron implementations.
What does 0 9 * * 1-5 do?
Runs at 09:00 Monday to Friday.
What if I set both day-of-month and day-of-week?
Standard cron runs on either match.
Do all systems use five fields?
Some, like Quartz and AWS, add seconds or a year field.