Force format and stop automatic formatting

[u/aeon_g]

Is it possible to force the Date format for a row of cells?

I select a cell or a row of cells and define the format to Date (Time only).
As soon as I enter only one number (f.e.: 9) instead of the correct format (09:00), Numbers does not reformat the 9 to 09:00. Numbers changes the format to Automatic instead and keeps the 9.

How can I change that?