What is a cron expression?
A cron expression is a shorthand for “when should this run?”. Systems like cron, CI pipelines, and cloud schedulers use it to describe repeating schedules in five fields. This tool parses the standard 5-field format into a plain-language description, a field breakdown, and the next five matching run times.
minute hour day-of-month month day-of-week
0–59 0–23 1–31 1–12 0–7 (0 and 7 = Sunday)
Values lists: 1,15 ranges: 9-17
Steps */15 (every 15) ranges with steps: 0-30/10
Names JAN, FEB ... DEC SUN, MON ... SAT
Field syntax
- Comma lists pick specific values:
1,15 means minutes 1 and 15. - Ranges cover a span:
9-17 hours is 09:00 through 17:00. - Steps repeat within a star or range:
*/15 every 15 minutes, 0-30/10 every 10 minutes in the first half hour. - Names work in the month and day-of-week fields: full or three-letter forms like
JANUARY/JAN and MONDAY/MON, case-insensitive. - Day-of-week accepts
0 and 7 for Sunday.
Shorthand aliases
Common schedules have names. Entering an alias expands to the equivalent 5-field expression, which is shown in the result as the normalized form.
@yearly 0 0 1 1 *
@monthly 0 0 1 * *
@weekly 0 0 * * 0
@daily 0 0 * * *
@hourly 0 * * * *
@annually and @midnight are also accepted as aliases of @yearly and @daily.
How days of the month and week combine
The standard format treats the day-of-month and day-of-week fields as an AND combination when only one of them is restricted. When both are restricted, a run fires when either matches — this is the classic Vixie behaviour, and this tool calls it out explicitly so the result never surprises you.
What is not supported
6- and 7-field second-based formats, and the Quartz or AWS dialect characters ?, L, W, and # are rejected with a clear message instead of being guessed at. If you paste one, switch to the equivalent standard 5-field form or use a scheduler that supports that dialect.
Timezones
Expressions are evaluated in your browser's local timezone from the current moment, and the next five runs are shown as local times. Cron on your server evaluates in the server's timezone, so a schedule that matches here may need adjusting when the system time differs.
Privacy
Everything runs entirely in your browser. Cron expressions and the computed run times are not uploaded to TechFixGen servers and are not included in analytics events.