UsefulTab
Cron Expression Explainer
Explain any cron expression and see its next run times.
Enter a cron expression to see what it means
Type a cron expression on the left to see a plain-English explanation of when it runs and the next five run times in your local time — all parsed in your browser.
Runs entirely in your browserExplain cron expressions and preview next runs, locally
Cron Expression Explainer parses a standard five-field cron expression — minute, hour, day of month, month, and day of week — and describes in plain English exactly when it fires. It understands the syntax crontab uses in practice: wildcards, step values like */15, ranges such as 9-17, comma lists, stepped ranges like 1-5/2, named months and weekdays (JAN-DEC, SUN-SAT), an optional leading seconds field, and shortcut macros such as @daily and @weekly. It then computes the next five run times in your own local time by walking forward from now, so you can sanity-check a schedule before deploying it. Everything is parsed in your browser — no expression is ever uploaded.
Common questions
What is a cron expression?
A cron expression is the compact schedule syntax used by cron and crontab to say when a job should run. The standard form has five space-separated fields — minute, hour, day of month, month, and day of week — each of which can be a specific value, a wildcard, a range, a list, or a step.
What order are the fields in?
Left to right: minute (0-59), hour (0-23), day of month (1-31), month (1-12 or JAN-DEC), and day of week (0-6 or SUN-SAT, where 0 and 7 both mean Sunday). If you supply six fields, the first is treated as an optional seconds field (0-59).
Which cron syntax is supported?
Wildcards (*), step values (*/n), ranges (a-b), lists (a,b,c), and stepped ranges (a-b/n), plus named months and weekdays. The macros @yearly, @annually, @monthly, @weekly, @daily, @midnight, and @hourly are also recognised and expanded to their equivalent expression.
What timezone are the next run times shown in?
They are computed in your browser's local timezone, matching your computer's clock. Cron on a server usually runs in that server's timezone, so if the machine you deploy to uses a different zone the actual times there will be offset accordingly.
Is my cron expression uploaded anywhere?
No. Parsing and the next-run calculation happen entirely in your browser tab using built-in date APIs. Your expression never leaves your device and nothing is stored.