[latexr]

The rule is that leap years are the ones divisible by 4. Unless it’s also divisible by 100. Unless unless it’s divisible by 400.

So 2000 was leap, but 2100, 2200, and 2300 won’t be, but 2400 will be.

[swores]

Ahh, so it's centuries that aren't divisible by 400 rather than that aren't divisible by 4, that makes more sense!

Thanks for answering

[thaumasiotes]

It's centuries that aren't divisible by 4. It isn't years that aren't divisible by 4.