Cron Expression Parser
Decode any cron expression into plain language and preview the next run times.
Free · No sign-up · Runs locally in your browser · Also available in Chinese (中文)
What is Cron Expression Parser?
A cron expression packs a schedule into five fields — minute, hour, day of month, month and day of week. Reading one from memory is error-prone, and a single wrong field silently schedules a job at the wrong time. The parser translates each field into plain language and shows the human meaning of the whole expression.
Because schedules are easier to verify by example, the tool also previews the next concrete run times computed from your expression. Seeing 'runs at 02:30 on weekdays' plus the next five timestamps makes it obvious whether the expression does what you intended before it goes into production.
How to use it
- 1Paste a cron expression such as 30 2 * * 1-5 into the input.
- 2Read the plain-language description of each field.
- 3Check the upcoming run times to confirm the schedule matches your intent.
- 4Adjust fields until the description and preview both look right.
Common use cases
- Reviewing a teammate's crontab entry before a deployment window.
- Writing a new scheduled task and verifying it before saving.
- Explaining a legacy job's schedule to someone who does not read cron.
Frequently asked questions
▸Which cron dialect is supported?
The standard five-field POSIX syntax is supported, including ranges, lists, steps and the */n form. Non-standard shortcuts like @daily map to their five-field equivalents.
▸Do day-of-month and day-of-week both restrict runs?
In classic cron, if both are restricted (not *), a day matches when either one matches — a common source of surprise that the plain-language preview makes visible.