Christmas day formula

The forum is locked. These are the original blitzbasic.com forums, kept so they can still be read. No new topics, replies or edits can be made here. To join in, head over to the Blitz3D+ forums.

Chroma

Actually 2045 is a bad test because it adds up to exactly 7 days so you can't tell if you had to rewind or advance.

Here's 2063:

1990=1
2000=2
2010=1
2020=2
2030=1
2040=2
2050=1
total=10

Advance 10 days from tuesday = friday
Rewind 10 days from tuesday = saturday

2060=friday
2061=sat
2062=sun
2063=mon

or

2060=sat
2061=sun
2062=mon
2063=tues

After checking it, the correct day is Tuesday. So we definitely REWIND when going forward in time.