Thanks a lot @awesomerobot for looking into it!
Does it also sometimes try to show just the month without the year to save space, or is that a separate bit of logic or a bug? I suspected that it had something to do with space limitations, and I tried different zoom levels but it doesn’t seem to make any difference, and I’m not sure why there’s inconsistency between Firefox and Chromium. For example:
And then I’m not sure why there’s a difference in the amount of space needed to display Mar 2020 (only shows Mar and only in Firefox) vs. Apr 2020 (shows the year too only with Firefox):
