I'm running 10.14.6. I was looking through the calendars in Language & Region settings (such as Coptic, Hebrew, Persian, etc) just because I was curious to see what they looked like. Then I changed back to Gregorian (the default) and found that the month (in this case "Apr") was missing from the menu bar. I tried restarting but that didn't help. I also tried fiddling around some more in settings but it's still the same.
For some reason, this thing won't let me add the URL so I put a space between the h and the t.
h ttps://i.imgur.com/o0Ovonu.png
For some reason, this thing won't let me add the URL so I put a space between the h and the t.
h ttps://i.imgur.com/o0Ovonu.png
I seem to have resolved this. I noticed that the "Show date" checkbox inside of Date & Time seemed to have become unchecked somehow even though I never touched it. Changing the calendar inside of Language & Region seems to have gotten the thing into a weird where just the "4" is shown in the menu bar without the "Apr" and the "Show date" checkbox is unchecked. It's very easy to reproduce but this bug isn't getting fixed.