backup: add time zone in examples

[3pointer]

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Add more details about backupts with time zone.

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[LGTM Timeline notifier]

Timeline:

• 2024-06-21 01:35:56.764721308 +0000 UTC m=+337883.250210135: ☑️ agreed by Oreoxmt.

[Oreoxmt]

/approve

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #17766.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.6: #17767.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.0: #17768.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #17769.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #17770.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #17771.