Frequently Asked Questions
Common questions about cron expressions, syntax, and how this parser works.
What is a cron expression?
A cron expression is a compact string of five whitespace-separated fields that defines a recurring schedule for automated jobs. The fields represent, in order: minute, hour, day of month, month, and day of week. For example, 0 9 * * 1-5 means "every weekday at 09:00".
What do the five fields in a cron expression mean?
The five fields are: 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). Each field can be a specific value, a wildcard (*), a range (1-5), a list (1,3,5), or a step (*/15).
How do I run a job every 5 minutes?
Use */5 * * * *. The */5 in the minute field means "every 5th minute starting from 0", so the job runs at :00, :05, :10, :15, and so on every hour.
What is the difference between * and */1?
They are functionally identical. * means "every valid value", and */1 means "every 1 step starting from the minimum", which resolves to the same set of values. Using * is the conventional shorthand.
Can I use day-of-week and day-of-month together?
Yes, but the POSIX standard specifies that when both fields are restricted (neither is *), the job runs when either condition is true (OR logic). For example, 0 0 1 * 1 fires on the 1st day of every month AND on every Monday — not just on Mondays that fall on the 1st.
How do I schedule a job for weekdays only?
Use the day-of-week field with the range 1-5 (Monday through Friday). For example, 0 9 * * 1-5 runs every weekday at 09:00. Sunday is 0 (or 7), Monday is 1, and Saturday is 6.
What does 0 0 1 * * mean?
0 0 1 * * means "at midnight (00:00) on the 1st day of every month". It is a common schedule for monthly maintenance tasks such as clearing logs or generating monthly reports.
Are month and weekday names supported?
Yes. You can use three-letter abbreviations for months (jan, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dec) and weekdays (sun, mon, tue, wed, thu, fri, sat). For example, 0 0 * jan mon runs every Monday in January at midnight.
Is this cron parser tool free and private?
Yes. The Cron Expression Parser on Computezy is completely free with no account required. All parsing and run-time calculations happen entirely in your browser — no data is ever sent to a server.
What is the valid range for each cron field?
Minute: 0–59. Hour: 0–23. Day of month: 1–31. Month: 1–12 (or jan–dec). Day of week: 0–7 (both 0 and 7 mean Sunday; 1 = Monday through 6 = Saturday).