This is the new behaviour in Yosemite and it can't easily be changed. The menu bar format now doesn't read your custom format and instead displays a barely customizable format instead. The only available options for it can be found in System Preferences
-> Date & Time
-> Clock
.
One thing you could do is use a third party utility like Day-O
, which is free and does exactly what you seek -> https://shauninman.com/archive/2016/10/20/day_o_2_mac_menu_bar_clock.
If you want things more natively, you could try editing the corresponding plist
file directly (com.apple.menuextra.clock
). I haven't however had much luck with it.
Open Terminal
and type the following:
Reading the current settings:
defaults read com.apple.menuextra.clock
Setting them:
defaults write com.apple.menuextra.clock "DateFormat" 'EEE hh:mm a'
Or 24 hours format with the (day of the) month and seconds:
defaults write com.apple.menuextra.clock "DateFormat" 'EEE d MMM HH:mm:ss'
Then refresh the menu bar using:
killall -KILL SystemUIServer
Using w
you should be able to add week number, but I haven't had any luck with that and it keeps resetting the week number.
yyyy-MM-dd, HH:mm • e/'w' – qqq,w
.