Build, read & preview the next run times of a cron schedule
Use *, */n, a-b, or a,b,c in each field. Day of week: 0–6 (0 = Sunday).
A tool for building and understanding standard 5-field cron expressions — fill in the five fields or pick a preset, and it shows the expression, a plain-English description, and the actual next 10 times it would run.
Fill in minute, hour, day, month, and weekday.
Read the description and next run times.
Copy the expression when it looks right.
Six common schedules — every minute, hourly, daily at midnight, weekdays at 9am, weekly, and monthly — are one click away, filling in all five fields at once so you don't have to build them from scratch for the common cases.
In order: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day
of week (0–6, where 0 is Sunday). A field left as * means "every value" for that
position.
Each field accepts * for every value, a-b for a range (like 1-5
for weekdays), */n for a step (like */15 for every 15 minutes), and
a,b,c for a specific list (like 1,15 for the 1st and 15th) — and these
can combine, such as 1-5/2.
Rather than approximating, the tool simulates forward minute by minute from right now (up to roughly 14 months ahead) and checks each one against your expression, so the 10 dates shown are the actual times it would next fire, not estimates.
When only one of day-of-month or day-of-week is restricted, only that one matters. When both are
restricted at the same time, standard cron uses OR logic: a day runs if it matches either field, not
only if it matches both. An expression like day-of-month 1,15 with day-of-week
5 runs on the 1st, the 15th, and every Friday — not just Fridays that happen to land
on the 1st or 15th.
No. This builds standard 5-field Unix cron. Quartz-style schedulers (used by tools like Salesforce and some Java job frameworks) add a seconds field and use somewhat different syntax, which this tool doesn't generate or parse.
No. This builds standard 5-field Unix cron (minute, hour, day-of-month, month, day-of-week). Quartz-style schedulers, used by tools like Salesforce, add a seconds field and use slightly different syntax, which isn't supported here.
No. Fields only accept numbers, ranges, steps, and lists (like 1-5, */2, or 1,15) — not three-letter day or month names, even though the schedule description below the expression does show names for readability.
With OR logic, matching standard cron behavior: if both fields are restricted (not *), a day runs if it matches either one, not only if it matches both. For example, "1,15" in day-of-month and "5" in day-of-week runs on the 1st, the 15th, AND every Friday.
It's a real simulation, checking minute by minute from now forward (up to about 14 months ahead) against your parsed expression, not an approximation, so the dates shown are the actual next times that expression would fire.
Not as typed shortcuts, but the six preset buttons cover the same common schedules (every minute, hourly, daily at midnight, weekdays at 9am, weekly, monthly) and fill in the equivalent five-field expression for you.
No. Parsing, validation, and the run-time simulation all happen entirely in your browser using JavaScript.