Date-Time Options Unclear

[Woodley]

I need to save files in a Date Time format:
YYYY-MM-DD__HHMMSS

I found the tooltip popup box that gives these commands, however it is NOT complete and I did not see any other options.
The problem with the current format using: %Y-%m-%d__%T is that it puts ':' in the file name: 2025-03-31__16:20:30
This is a problem in the file naming convention on most systems. I need the Time format to show as 164518 format using the 24 hour clock.
2025-03-31__164518

When I tried to use a lower case %t it does not give a time.

When clicking on the help menu it forces me to sign into GitHub and submit the question in this manner rather than searching for the information myself. Please include better instructions and help options in future versions.

After further searches on other websites, I did figure out that I could use:
%Y-%m-%d__%H%M%S
or
%F__%H%M%S

Results:
2025-03-31__130540.png

This allows all screenshots to stay in order by filename regardless of the name of the specific page or window, which in some cases can exceed file name length limitations.

[Photon89]

You can use %H for hours, %M for minutes and %S for seconds. Further wildcards can be found by executing man date or date --help in a terminal.

We could include this as a hint in the tooltip.