However I’m always annoyed that the month parameter when constructing a date object is 0 based. So 1st of Jan is

new Date(2024, 0, 1)

That’s nothing. The ‘tm’ type in the C standard library also starts months at 0. But the year 0 is the actually the year 1900.

So 1. january 2024 would be

tm date{ .tm_mday=1, .tm_mon=0, .tm_year=124 };.