A cron expression has five fields separated by spaces. Each field controls one part of the schedule, from minutes on the left to the day of the week on the right.
* * * * * │ │ │ │ │ │ │ │ │ └─ day of week (0–6, Sun–Sat) │ │ │ └─── month (1–12) │ │ └───── day of month (1–31) │ └─────── hour (0–23) └───────── minute (0–59)
Each field accepts a single value (5), a list (1,15,30), a range (1-5), a step (*/10 means "every 10"), or an asterisk (*) meaning "every value". Combine them to express almost any recurring schedule.
For example, 0 9 * * 1-5 runs at 9:00 AM on weekdays. Cron jobs run in the server's time zone, so always confirm whether your scheduler uses UTC or local time — the preview above is in UTC.