 # How to do calendar calculations

Dude please teach me how to mental calendar calculations day

How it works

There is a tutorial here:

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Thankyou very much

There are two things you might want to consider when following the algorithm in this post.

1. If you are looking at the normal ranges used in competition:
a) Jan 1, 1600 - Dec, 31, 2099 @ 1 minute
b) Current century (2000 - 2099) @ 20 dates

…you are better off adding 1 to the century codes, so that 2000 and 1600 are 0. That way you can completely ignore the century when doing the current century, plus there is a 40% chance that you don’t need to calculate the century for the 1600-2100 range.

N.B.: if you add 1 to the century, you have to deduct 1 from the month. So instead of Jun 2000 being 4 (June) + 6 (20__) = 10 / 7 = 1 remainder 3; you are looking at 3 (June) + 0 (20__) = 3.

2. Rather than using a slow formula for the year code, simply place them in seven distinct memory palaces and use reverse lookup to get the code for the year.

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