Change the menubar clock format…

In a Terminal window, type:

defaults write -g AppleICUTimeFormatStrings -dict-add 2 “MMMM d, y hh’:’mm’:’ss’ ‘a”

Press Return and then type:

killall SystemUIServer

Press Return again and the menu bar will disappear — click anywhere on the desktop to reload it, if necessary. Bingo…Long format clock.