Crontab Every 15 Minutes (*/15 * * * *)
Run a cron job every 15 minutes with the */15 step expression. A balanced frequency for data sync, cleanup, and reporting tasks.
Detailed Explanation
Running a Cron Job Every 15 Minutes
The expression */15 * * * * schedules a job at the 0th, 15th, 30th, and 45th minute of every hour. This is one of the most balanced frequencies for recurring tasks.
Field Breakdown
| Field | Value | Meaning |
|---|---|---|
| Minute | */15 | Every 15th minute |
| Hour | * | Every hour |
| Day of Month | * | Every day |
| Month | * | Every month |
| Day of Week | * | Every day |
Quarter-Hour Scheduling
The 15-minute interval divides each hour into exactly four execution windows. This makes it predictable and easy to reason about:
- :00 (top of the hour)
- :15 (quarter past)
- :30 (half past)
- :45 (quarter to)
This predictability is valuable when coordinating multiple jobs or when users expect data to refresh at regular intervals.
Execution Count
This schedule runs 96 times per day (4 times per hour x 24 hours) and 2,880 times per month — enough for timely processing without excessive resource consumption.
Alternative Syntax
You can achieve the same schedule with an explicit list: 0,15,30,45 * * * *. Both forms are equivalent, but the step syntax is more concise and conventional.
Use Case
Perfect for data synchronization jobs, report generation that feeds dashboards, log rotation checks, temporary file cleanup, email digest processing, or any task where near-real-time is not required but hourly is too infrequent.