The Duodecimal Bulletin, Vol. 55, No. 1, Year 1209 [pdf]

I'm more of a seximal man myself: https://www.seximal.net/

What's the deal with that upside-down 2 on the title page? I first thought it would be one of the two additional digits, but those are visible on the "clock face" circle on the first page and look nothing like it.

(or are upside-down digits their way to mark icky base-10 numbers if they have to write them?)

Edit: ah, they explain it on page 23.

12 is, in many ways, a better base than 10 (divisible by 2,3,4 and 6 vs 2 and 5). And it was used in many British/Imperial units. But the chance of the world moving existing systems from base 10 to base 12 is surely so close to 0 as makes no difference?

1209 is 2025, to answer the first question I had.