Cron Expression Generator
Build cron expressions from dropdowns with an instant human-readable preview of when the job will run.
About Cron Expression Generator
Cron expressions are compact and powerful, but their five-field syntax is easy to get wrong — one wrong digit can make a job run every minute or never at all. This builder turns the schedule into a visual form, so you choose when a job should run and the tool produces the exact expression.
Pick a schedule type like daily, weekly, or monthly, set the time and day, and the tool writes the five-field expression while showing a human-readable description of when it fires. Pasted expressions can also be read back to confirm what they mean. The output works with cron on Linux servers and most schedulers that follow the same format.
Backend developers and DevOps engineers use it when writing cron jobs for backups, batch processing, and report generation, while system administrators use it to schedule maintenance tasks. It's equally handy for anyone maintaining deployment configs that define scheduled jobs in code.
How to Use
- Choose the schedule: minute, hour, daily, weekly, monthly, or yearly.
- Pick the specifics like time and day.
- Copy the generated cron expression.
Example
Daily at 2:30 AM 30 2 * * *
The five fields are minute, hour, day of month, month, and day of week. '30 2 * * *' runs at 02:30 every day.
FAQ
What do the five cron fields mean?
Minute, hour, day-of-month, month, and day-of-week. Asterisks mean 'every', so '* * * * *' runs every minute.
Does it support more advanced expressions?
The builder covers the common schedules visually; for complex expressions, paste an existing one to see its meaning.
What timezone does cron use?
Cron runs in the server's configured timezone. This tool previews times in your local timezone, so check your server config.
Can I use this with Kubernetes CronJobs?
Yes. Kubernetes CronJobs accept standard cron expressions in their schedule field, so the output pastes directly into the spec. Just note that Kubernetes uses UTC by default, so confirm the timezone matches your intent.
Why does cron sometimes skip my scheduled job?
Cron skips jobs most often when the server's timezone differs from what you intended, or when the service wasn't running when the time passed — cron doesn't backfill missed runs. Specifying both day-of-month and day-of-week can also behave unexpectedly, so keep one of them as an asterisk.