What does this cron
expression mean?

Cron field reference

A standard cron expression has 5 fields, in this order: minute hour day-of-month month day-of-week. Each field accepts a number, a * wildcard (any value), a range like 1-5, a list like 1,3,5, or a step like */15 (every 15 units). If both day-of-month and day-of-week are restricted (not *), cron treats them as OR, not AND — the job runs when either condition matches.

Common examples

• */5 * * * * — every 5 minutes
• 0 9 * * 1-5 — 9:00 AM on weekdays
• 0 0 1 * * — midnight on the 1st of every month
• 0 0 * * 0 — midnight every Sunday