19991231 base day 730118, Friday in week 365 of year
20000229 base day 730178, Tuesday in week  60 of year
20000301 base day 730179, Wednesday in week  61 of year
20240229 base day 738944, Thursday in week  60 of year
20261012 base day 739900, Monday in week 285 of year
19700101 base day 719162, Thursday in week   1 of year
19001231 base day 693959, Monday in week 365 of year
days from 2000-01-01 to 2026-10-12: 9781
2000 leap: 1  1900 leap: 0  2024 leap: 1
date from base day 740000: 20270120
last day of each month 2024:
31 29 31 30 31 30 31 31 30 31 30 31
