Cron expression builder & parser
Build cron expressions by picking minutes, hours, days, months, and weekdays — or paste an existing expression to parse it into plain English.
About this tool
A cron expression is five fields — minute, hour, day of month, month, day of week — and the syntax is compact enough to write quickly and cryptic enough to misread. The usual failure is not a syntax error but a schedule that parses fine and runs at the wrong time, which you discover when a job fires every minute for an hour instead of once. Two rules cause most of the confusion. First, the day-of-month and day-of-week fields are ORed rather than ANDed when both are restricted: an expression asking for the 1st and for Monday runs on every 1st and every Monday, not on Mondays that fall on the 1st. Second, cron has no time zone of its own — it uses the system's, which means a schedule can shift by an hour at daylight saving transitions, skip a run in the spring gap, or fire twice in the autumn overlap. This tool parses an expression into plain English, builds one from the fields, and lists the next scheduled run times so you can verify the schedule before deploying it.
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Type a cron expression directly to see its human-readable description, or use the visual builder to set minute, hour, day, month, and weekday fields.
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The next 5 scheduled run times are shown so you can verify the schedule is correct.
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Use the presets for common schedules like every hour, daily at midnight, or every weekday.
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Click Copy to use the expression in your cron job, CI pipeline, or cloud scheduler.
Build cron schedules for CI/CD pipelines, cron jobs, and serverless functions.
Parse an existing cron expression from a Dockerfile or server config to understand when it runs.
Preview the next 5 run times for a cron schedule before deploying.
Every 5 minutes
*/5 * * * *Every 5 minutesEvery weekday at 9 AM
0 9 * * 1-5At 09:00 AM, Monday through FridayFirst day of every month
0 0 1 * *At midnight on the 1st of every monthThe job runs far more often than intended
Cause: An omitted field. Writing 5 * * * * means minute 5 of every hour, twenty-four times a day; the intended once-daily schedule needs an hour value, as in 5 3 * * *. A * left in the minute field means every minute of the matching hour.
Fix: Check the human-readable description and the list of next run times before deploying. If the gap between consecutive runs is not what you expect, the expression is wrong regardless of how it reads.
Restricting both day-of-month and day-of-week gives extra runs
Cause: Standard cron ORs the two day fields when neither is *. This surprises almost everyone, because every other pair of fields is ANDed.
Fix: Restrict only one of the two day fields and leave the other as *. To require a specific weekday within a date range, do the date check inside the job rather than in the expression.
The job fires an hour late or is skipped twice a year
Cause: Daylight saving. A job scheduled at 02:30 does not run at all on the spring-forward date and runs twice on the autumn date in some implementations.
Fix: Schedule sensitive jobs outside the 01:00 to 03:00 window, or run the scheduler in UTC. Most modern schedulers accept an explicit time zone — set it rather than relying on the host's.
These answers explain common cron builder tasks, expected input formats, and edge cases so both visitors and search engines can understand what this tool does.
What is a cron expression?
A cron expression is a string of 5 fields (minute, hour, day-of-month, month, day-of-week) that define a recurring schedule. For example, '0 9 * * 1-5' means 9:00 AM every weekday.
What does * mean in a cron field?
'*' means 'every'. For example, '* * * * *' means 'run every minute of every hour of every day'.
Can I use ranges and step values?
Yes. Ranges are written as 1-5, lists as 1,3,5, and step values as */15 (every 15 units) or 0-30/5 (every 5 units from 0 to 30).
What do the five fields in a cron expression mean?
From left to right: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–7, where both 0 and 7 represent Sunday). For example, '0 9 * * 1' means 'every Monday at 09:00'.
Does this tool support the @yearly, @monthly, or @daily shorthand?
The builder generates standard five-field cron expressions. Common shorthands like @daily (0 0 * * *), @weekly (0 0 * * 0), @monthly (0 0 1 * *), and @yearly (0 0 1 1 *) can be entered directly if your cron runner supports them.