Big Sur doesn't allow me to change date/time format in menu bar

Go to Settings > Dock & Menu Bar > Clock and untick "Use a 24-hour clock", and enable "Show AM/PM" if you want.

Hi, I'm trying to do this too to no success now that with Big Sur YOU CANNOT REMOVE THE CLOCK from the menu anymore because it's tethered to notifications. So, now I have two clocks on Big Sur. Apple once again "fixing" things that aren't broken. I've left feedback, but Apple has never changed anything I've suggested, so I seriously doubt anything will come of this.

I use iStat Menus which has an infinitely better clock, but I guess it's tough luck now.

I want:

2020 Nov 15 15:48.52 Sun

iStat Menus does this perfectly.

If Big Sur could do this, I wouldn't be griping. But, when I put all that into the "Language and Region" but it doesn't change the menu bar clock at all. It still says "Sun Nov 15 15:48:52".

I cannot for the life of me figure out how to change the display to what I want. I changed the format in "Language and Region" but it didn't change the menu clock at all.

My "fix" is to reduce the clock to as little wasted space as possible, and go to Preferences>Dock & Menu Bar>Clock and reduce everything to as small as possible (3:48) and keep my iStat Menus clock.

This update should have been called Big Mess. Unfortunately, I made the mistake of turning on automatic updates for systems, so I'm just out of luck.

Well this is crap. I go to the Dock/Menu Bar prefs for Clock, and deselect Show the day of... and Show date, but nothing changes. the options to change are there and I can toggle, but I still have Day of Week, Date, and time. Can't change to analog either and like others, I use iStat which is WAY better. Now I'm stuck with two date/time items in menubar. wtf?

I'm less concerned about the format, but I want to be able to change time & date settings from the menu bar, but appear to be unable since updating to Big Sur. Is the only way to change the time/date by going into settings?

Yes, Apple come on, it can't be that hard to fix this irritating formatting issue in the menu bar.

I want to be able to get 2021-03-05 hh:mm or 21-03-05 hh:mm.

And when you click it, it shows notices, move it to its own. Who is the UI genius on this?

click the lock to make changes

Go to Settings > Dock & Menu Bar > Clock and untick "Use a 24-hour clock", and enable "Show AM/PM" if you want. After this restart the PC. It worked for me.

Thank you for this! I was having the same issue too after upgrading and this solved it! thank you! :)