Sean on Nostr: This is how you work out whether a particular year is a leap year: On every year that ...

This is how you work out whether a particular year is a leap year:
On every year that is divisible by 4 with no remainder.
Except every year that is divisible by 100 with no remainder.
Unless the year is also divisible by 400 with no remainder
2100 is 19 4-year cycles from now and will be a halving year, but not a leap year.
All your models are broken.