Add ability to override the timezone for backup jobs

[eminaktas]

Proposal

Operator utilizes "github.com/robfig/cron/v3" to enable cron jobs for backups. When I check the source, they support overriding the default timezone with TZ and CRON_TZ (recommended way) environment variables. It is mentioned here.

They also allow us to override timezone based on jobs. You can see Location parameter in SpecSchedule struct here.

There is also another option that doesn't require any code change which is explained here.

Use-Case

We would like to create multiple database services and they will serve different timezones. With this change, with single operator, we will be able to schedule backup jobs based on any timezone.

Is this a feature you are interested in implementing yourself?

Yes

Anything else?

No response

[eminaktas]

I just noticed after looking a bit more, they are already providing this as a feature. Look this explanation. Since the operator container is missing the timezone details inside the container, it fails the load. It requires very simply solution.

It requires this instruction in the Dockerfile: COPY --from=go_builder /usr/share/zoneinfo /usr/share/zoneinfo

This is how the config looks like

    schedule:
    - keep: 3
      name: backup
      schedule: CRON_TZ=Asia/Tokyo 0 5 * * 1-5
      storageName: fs-pvc

Here is the log output

2025-08-12T12:50:12.349Z    INFO    Creating or updating backup job    {"controller": "pxc-controller", "namespace": "percona-operator-test", "name": "testing-mysql-with-timezone", "reconcileID": "2ce02b4b-24c9-4d9e-b1ae-ec6bc6d8e13e", "name": "3314a-backup", "schedule": "CRON_TZ=Asia/Tokyo 0 5 * * 1-5"}