date/time not showing in menu bar 12.6.3 mini, late 2014

This is a long shot but try booting into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

Any possibility the User is using the applications in Full Screen Mode

I too am on Ventura 13.2.1 and when in Full Screen Mode refer to image below

The entire Menu Bar at Top disappears including Date, Time and all our icons normal appearing there

c. elhardt wrote:

Thanks, Luis. I don't use them either and on inspection the night and focus sliders were off. Say, you're not the Luis Sequeira related to Javier in Florida, are you?

No, I'm from the other side of the Atlantic... I'm from Portugal.

Did you check both the settings in "Dock & Menu Bar" and in "Date & Time"?

I am on Ventura, and things look different, but I recall that both of these had options to show or not show the date, and maybe there are conflicting.

I never use them, but some settings under "Do not disturb" or "Focus" can result in the date and time not appearing.