Cron Expression Builder
A cron expression is a five field string (minute, hour, day of month, month, day of week) that defines when a scheduled job runs. */5 * * * * means “every 5 minutes”; 0 9 * * 1-5 means “9 AM on weekdays.” Build expressions interactively below, read a plain English translation, and check the next run times before deploying.
How to Use
- Pick a preset or start typing a cron expression in the field inputs
- Edit individual fields. Each input corresponds to one cron field (minute, hour, day, month, weekday)
- Read the explanation. The tool translates your expression to plain English in real time
- Check next executions. Verify that the schedule fires when you expect
- Copy the expression and paste it into your crontab, Kubernetes manifest, CI config, or scheduler
Cron Syntax in Detail
Each of the five fields accepts these value types:
*every possible value for that field5a specific value1,3,5a list of values1-5a range (inclusive)*/10a step (every 10th value starting from the field minimum)5-20/3a step within a range (5, 8, 11, 14, 17, 20)
The month field accepts 1-12 or three letter names (JAN through DEC). The day of week field accepts 0-6 (Sunday=0) or names (SUN through SAT). Some implementations also treat 7 as Sunday.
Common shorthand aliases like @daily (equivalent to 0 0 * * *), @hourly (0 * * * *), and @weekly (0 0 * * 0) are supported by most cron implementations and by this tool.
The trickiest behavior in cron is the day of month / day of week interaction. When both fields are restricted (neither is *), POSIX cron runs the job when either condition matches, which is OR logic, not AND. This catches many people off guard. If you set 0 0 15 * 5, the job runs at midnight on the 15th and on every Friday, not just on Fridays that fall on the 15th.
Need to convert the execution times to a different timezone? The Unix Timestamp Converter can help you work with timestamps across timezones.