Cron expression builder
Translate a cron schedule into plain English and see the next run times.
Five fields: minute · hour · day-of-month · month · day-of-week
This cron expression generator lets you paste an existing expression and have it translated into plain English. It shows the next several run times so you can confirm the schedule fires exactly when you intend, before you commit it to a server. That removes the guesswork from tricky patterns like ranges, steps, and day-of-week overlaps. Building a correct schedule is only half the job, though; SJ Monitor's cron and heartbeat monitoring then tells you if a scheduled run silently fails to execute.
Frequently asked questions
What do the five cron fields mean?
From left to right they are minute, hour, day of month, month, and day of week. The tool labels each field and explains the value you enter.
How can I tell if a cron job actually ran?
A cron expression only defines the schedule, not whether the job succeeded. SJ Monitor's cron and heartbeat monitoring expects a check-in for each run and alerts you when one is missed.
Does this support step and range values?
Yes. Steps like */15 and ranges like 1-5 are parsed and described in plain English, with next run times reflecting them.
What does */15 mean in a cron field?
It's a step value meaning "every 15 units" of that field — in the minute field, */15 fires at :00, :15, :30, and :45. Steps can combine with ranges, so 0-30/10 runs every 10 minutes only within the first half-hour.
What time zone do cron schedules use?
Traditional cron runs in the server's local time zone, so a schedule can shift across daylight-saving changes. Confirm the time zone of the machine running the job, since this tool computes next runs in a fixed reference.
How do overlapping day-of-month and day-of-week work?
When both fields are restricted (not *), standard cron treats them as OR, running if either matches — a frequent source of unexpected extra runs. The plain-English output makes this explicit.
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