Question 1

What format does the cron expression use?

Accepted Answer

The classic 5-field format: minute, hour, day of month, month, day of week (e.g. 0 9 * * 1-5 means 9:00 AM every weekday). Nicknames like @daily, @hourly, and @weekly are also supported.

Question 2

What timezone are the next-run times shown in?

Accepted Answer

Your browser's local timezone. There's no server involved, so times are computed relative to your own device's clock and timezone setting — keep that in mind if the schedule will actually run on a server in a different timezone.

Question 3

Why does it say my expression is invalid?

Accepted Answer

A cron expression needs exactly 5 fields (or a valid @nickname). Check for a missing field, an out-of-range value (e.g. hour 25), or a typo in a weekday/month name.

Question 4

What do the special characters mean?

Accepted Answer

* matches any value, , separates a list (1,15), - defines a range (1-5), and / defines a step (*/15 means every 15 units). These can be combined within a single field.

Question 5

Is my cron expression sent anywhere?

Accepted Answer

No — parsing, describing, and computing next-run times all happen entirely in your browser.

Cron Expression Parser

Frequently asked questions