Change backup file naming structure

What problem will this feature address?

The current backup file naming convention includes a timestamp formatted as YYYY-MM-DDTHH:MM:SS.SSSZ.tar. This format contains a colon (:) which is not supported by Windows 11 for file names. As a result, when downloading these backup files, they get truncated and renamed, making it difficult to identify the contents. For example, a file might be renamed to D3HQ44~0.TAR, obscuring its original purpose.

Describe the solution you'd like

I propose that the timestamp in the backup file name be modified to use an alternative format that is compatible with Windows file naming conventions. One suggestion is to replace the colons with hyphens or underscores, for example: YYYY-MM-DD_HH-MM-SS_SSSZ.tar. This would ensure that users on all platforms can easily download the files without them being renamed or truncated.

Describe alternatives you've considered

Make it customizable so users with different needs (and using different OS) will use the format they prefer

Additional context

A consistent and clear naming structure would enhance the user experience significantly.

Will you send a PR to implement it?

No

No file, entry point, or test is named in the issue. Search the repository for the current backup timestamp pattern and the code that generates backup filenames, then inspect any related tests. Done means generated names avoid Windows-invalid colons while preserving an identifiable timestamp, with coverage for the new format.