What does concurrencyPolicy: Forbid do?

It prevents a new job from starting if the previous run is still active. This avoids overlapping executions for long-running daily jobs.

Kubernetes CronJob Daily

0 0 * * *

Every day at 12:00 AM

Next 10 Executions

Times shown in UTC

Tue, May 19, 202600:00
Wed, May 20, 202600:00
Thu, May 21, 202600:00
Fri, May 22, 202600:00
Sat, May 23, 202600:00
Sun, May 24, 202600:00
Mon, May 25, 202600:00
Tue, May 26, 202600:00
Wed, May 27, 202600:00
Thu, May 28, 202600:00

Field Breakdown

0

Minute

0

Hour

*

Day of Month

Every day

*

Month

Every month

*

Day of Week

Every day of week

About This Schedule

To schedule a daily Kubernetes CronJob at midnight UTC:

spec:
  schedule: "0 0 * * *"
  concurrencyPolicy: Forbid

Daily CronJobs are used for database backups, log cleanup, certificate renewal checks, daily data processing, and cluster maintenance tasks. Setting concurrencyPolicy: Forbid prevents overlapping runs if yesterday's job hasn't finished.

Important settings for daily jobs: set startingDeadlineSeconds to a reasonable value (e.g., 3600 for 1 hour) so the job still runs if it misses its exact schedule. Set backoffLimit to control retries on failure. And always set resource requests and limits on the container to prevent daily jobs from starving other workloads.