Is Sunday 0 or 7 in cron?

Both are valid. Sunday can be represented as 0 or 7 in most cron implementations, though 0 is more universally supported.

What is the cron expression for Sunday at 8 AM?

The expression is 0 8 * * 0 (or equivalently 0 8 * * 7).

Cron Sunday at 8 AM

0 8 * * 0

Every Sunday at 8:00 AM

Next 10 Executions

Times shown in UTC

Sun, May 24, 202608:00
Sun, May 31, 202608:00
Sun, Jun 7, 202608:00
Sun, Jun 14, 202608:00
Sun, Jun 21, 202608:00
Sun, Jun 28, 202608:00
Sun, Jul 5, 202608:00
Sun, Jul 12, 202608:00
Sun, Jul 19, 202608:00
Sun, Jul 26, 202608:00

Field Breakdown

0

Minute

8

Hour

*

Day of Month

Every day

*

Month

Every month

0

Day of Week

Sun

About This Schedule

The cron expression 0 8 * * 0 triggers every Sunday at 8:00 AM. Sunday is often the quietest server day, making it ideal for resource-intensive maintenance tasks.

This schedule is commonly used for full database dumps, weekly log rotation and archival, extended health checks, performance benchmarking, and pre-Monday preparation tasks. Running at 8 AM gives on-call staff daylight hours to respond if something goes wrong.

In cron, Sunday can be represented as either 0 or 7. Both are valid, but 0 is more universally supported across different cron implementations.