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Cron Expression Explainer

Read any cron expression in plain language, field by field, and see exactly when it will run next.

Common schedules:

Next runs Time zone:

How to Use

1. Type or paste a cron expression, or pick one from Common schedules.
2. Read the plain-language description and the five fields below it.
3. Check the next run times in this device's time zone or in UTC; choose 5, 10 or 20 runs.
4. Fix any field marked in red: the message says what is wrong.

Names such as MON or JAN, ranges, lists, steps and macros such as @daily are understood. Everything runs in your browser.

Frequently Asked Questions

What do the five fields mean?

From left to right: minute (0 to 59), hour (0 to 23), day of month (1 to 31), month (1 to 12 or JAN to DEC) and day of week (0 to 6 or SUN to SAT, where 7 is also Sunday).

What does */15 mean?

Every 15th value of the field, starting from its lowest: in the minute field, minutes 0, 15, 30 and 45. 5/15 would start at 5 instead: 5, 20, 35 and 50.

What happens when both day of month and day of week are set?

In standard cron, the job runs on any day that matches either field. 0 0 1 * 1 therefore runs on the 1st of every month and on every Monday, not only on Mondays that fall on the 1st.

Which time zone does cron use?

The time zone of the machine or service running it, often UTC on servers and in cloud schedulers. Compare the next runs in both zones here to avoid being an hour or more off.

Does it support seconds?

No. Standard cron has five fields. Six- and seven-field expressions from Quartz or Spring include seconds and are reported rather than misread.

Cron Expression Explainer - What Your Crontab Line Really Means

Updated September 29, 2026 · By Saman

Paste a cron expression and read it as a plain sentence, see each of the five fields on its own, and check the next run times in your own time zone or in UTC. It catches the mistakes that make a job run at the wrong time: a value out of range, a six-field expression copied from Quartz, or a schedule that can never happen, such as 31 February.

Cron is the scheduler behind Linux and macOS crontabs, and its syntax is also used by Kubernetes CronJobs, GitHub Actions, GitLab CI and most cloud schedulers. The syntax is compact and easy to misread; a quick check here saves a job that runs every minute instead of once a day.

How to use it

Type or paste a cron expression, or pick one from Common schedules.
Read the description and the five fields below it.
Check the Next runs list; switch Time zone between This device and UTC.
If a field is outlined in red, the message above it says what is wrong.

The five fields

Field	Allowed values	Example	Meaning
Minute	0–59	`30`	At minute 30
Hour	0–23	`9-17`	From 09:00 to 17:59
Day of month	1–31	`1,15`	On the 1st and 15th
Month	1–12 or JAN–DEC	`*/3`	January, April, July, October
Day of week	0–6 or SUN–SAT (7 = Sunday)	`1-5`	Monday to Friday

Special characters

* means every value of the field.
, separates a list: 1,15,30.
- gives a range: 9-17.
/ gives a step: */15 is every 15th value from the lowest, 5/15 every 15th from 5.
Macros replace the whole line: @hourly, @daily, @weekly, @monthly, @yearly.

The day-of-month and day-of-week trap

When both day fields are restricted, standard cron runs the job on days that match either of them, not both. 0 0 1 * 1 runs at midnight on the 1st of every month and also every Monday. People usually expect "Mondays that fall on the 1st", which plain cron cannot express. The tool shows a note whenever both fields are set, and the next runs list makes the real behaviour obvious.

Time zones

Cron uses the time zone of the machine or service that runs it. Servers and cloud schedulers such as GitHub Actions usually run in UTC, so a job written for 09:00 may fire at 09:00 UTC, which is a different hour in most places, and it shifts by an hour when daylight saving time starts or ends where you live. Compare the next runs in This device and UTC to see the difference before you deploy.

What this tool does not support

Seconds: six- and seven-field expressions from Quartz and Spring are reported rather than misread.
Non-standard extensions such as L, W and #, which some schedulers add.
@reboot, which runs once at start-up and has no next time.

Related tools

To turn a run time into a Unix timestamp or back, use the timestamp converter. The task pages open this tool with a common schedule: every 5 minutes, every hour and every day at midnight.