2026-06-10
How to read cron expressions
Learn the five fields of a standard cron expression and common scheduling pitfalls.
A standard cron expression has five fields: minute, hour, day of month, month, and day of week. For example, */15 9-17 * * 1-5 describes a repeating schedule during weekday business hours.
Use the Cron Expression Parser to label each field. Use the UTC Time Converter when a scheduler runs in UTC.
Common pitfalls
The expression is only part of the schedule. The runtime timezone matters, and different platforms may support different cron extensions.
Change management
Before editing a production cron job, write the expected next run time in plain language. This reduces the chance of a schedule being correct syntactically but wrong operationally.