A cron expression is a string of 5 fields (minute, hour, day-of-month, month, day-of-week) that defines a schedule. For example, "0 9 * * 1-5" means 9:00 AM every weekday.

The slash means "every N". So */5 in the minute field means every 5 minutes (0, 5, 10, 15, ...). You can also use ranges like 1-30/5 for every 5 minutes from 1 to 30.

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