That's similar to the Shire calendar system[1]. It has twelve months of 30 days, but the missing days are not in any month.

1: https://tolkiengateway.net/wiki/Shire_Calendar

And also similar to the French Revolutionary calendar (1793 to 1805) which had twelve 30-day months and 5 or 6 jours complémentaires.

I like that Tolkien’s legendarium got the first mention here though.

The ancient Roman calendar was before that, with 10 months of 30 or 31 days and intercalated days when it's no month at all.

Sometimes priests moved these days to suit political shenanigans.

Caesar ended this madness and "rationalised" the system, coincidentally making his year-long consulship last for 446 days.

Wasn't Tolkien's LOTR partly inspired by Ethiopia?

More likely the Roman calendar.

That no odder than Gregorian

Still not weirder than Lunar calendar

Why use celestial bodies at all? Let's bring the Soviet calendar back!

something something every 5 years.

It's not odd as in a more unusual system, but odd in that it is widely incompatible with the calendar of most of the world, but still official calendar. Kinda like the Kodak calendar (which was instead 13 28-day months (364 days), and iirc does the off-day adjustments over the corporate winter holiday...actually pretty reasonable)

Merry Corporate Winter Holiday!

lmao

Not reasonable at all... it's Corporate Summer Holiday around here.

You take that back!

There are good reasons for the Gregorian calendar’s oddities, though. Any simple system stops being simple when you apply it to enough different situations. I am not sure programmers would like it better if each country had a different calendar for each season. Because a day that starts at 6 and ends at 18 would make sense 2 days each years here in Europe. Not even that if you go far enough North.

I'm actually quite a fan of perennial calendars like that, I think the Ethiopian calendar is a much more logical system than the Gregorian system.

Almost every calendar system has a similar trick: https://en.wikipedia.org/wiki/Intercalation_(timekeeping)

The west inherits from the Romans, and Julius Caesar standardized away the Roman intercalary month by glomming it into Feburary. Before that a "priest" (the pontifex maximus) (in scare-quotes because it was a political office) would add that month on an ad-hoc basis. Not so different!