Question 1

What is a cron expression?

Accepted Answer

Cron expression is a string that defines when a scheduled job runs. Format: 5 fields separated by spaces - minute hour day-of-month month day-of-week. Each field specifies allowed values (0-59 for minutes, 0-23 for hours, etc.). Special characters like * (any), / (step), - (range) provide flexibility.

Question 2

How do I schedule a cron job to run every hour?

Accepted Answer

Cron expression for every hour: 0 * * * * (at minute 0 of every hour). Or use shorthand: @hourly. For every 6 hours: 0 */6 * * *. For specific hours like 9am and 5pm: 0 9,17 * * *. The first field (minute) determines when within the hour; 0 = start of hour.

Question 3

How do I schedule a cron job for weekdays only?

Accepted Answer

Weekdays cron (Monday through Friday): * * * * 1-5. Common pattern for business hours: 0 9-17 * * 1-5 (every hour from 9am-5pm on weekdays). Day of week: 0=Sunday, 1=Monday, ..., 5=Friday, 6=Saturday, 7=Sunday (alternative). Use 1-5 for weekdays, 0,6 for weekends.

Question 4

What does */5 mean in cron?

Accepted Answer

*/5 means 'every 5 units' in that field. */5 * * * * = every 5 minutes (at 0, 5, 10, 15...). */10 in hour field = every 10 hours. */15 in minute field = every 15 minutes. The / character defines step values - execute at regular intervals starting from the first value in range.

Question 5

Where are cron jobs used?

Accepted Answer

Cron jobs used in: Linux/Unix (crontab), Kubernetes (CronJob), AWS (EventBridge Rules), GCP (Cloud Scheduler), Azure (Time-based triggers), Jenkins (build schedules), CI/CD pipelines, backup systems, log rotation, email newsletters, database cleanup, report generation, monitoring checks.

Cron Expression Generator

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