Monday, February 11, 2008

I Like Ike Calendar

In 1952, Professor Egghead's father voted for Dwight Eisenhower for US President and had kept the calendar as a keepsake. Recently, Professor Egghead was going through some of his father's keepsakes and discoverd this calendar from 1952 and noticed that all the dates in 1952, which was a leap year, coincided exactly with the dates in 2008, which is also a leap year.

This made the professor wonder, how many different calendars would you need to have in order to represent every possible combination of yearly calendar?

3 comments:

  1. In a normal year there would be 52 weeks and 1 extra day, so in leap years there would be two extra days.

    Year = which day it starts on
    _____________________________

    Year 1= monday
    Year 2= tuesday
    year 3= wednesday
    Year 4= thursday (leap year)
    Year 5= saturday
    Year 6= sunday
    Year 7= monday
    Year 8= tuesday (leapyear)
    Year 9= thursday
    Year 10= friday
    Year 11= saturday
    Year 12= sunday (leapyear)
    Year 13= tuesday
    Year 14= wednesday
    Year 15= thusrday
    Year 16= friday(leap year)
    Year 17= sunday
    Year 18= monday
    Year 19= tuesday
    Year 20= wednesday (leap year)
    Year 21= friday
    Year 22= saturday
    Year 23= sunday
    Year 24= monday (leap year)
    Year 25= wednesday
    Year 26= thursday
    Year 27= friday
    Year 28= saturday (leap year)
    Year 29= monday

    This proves that you only need 28 different calenders.
    The reason I have put monday on a 29th year is because that is when the wole cycle starts again.



    By the way, I am only 13.

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  2. well since you skip leap years there may be some problems with this theory bug sure.

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  3. You need 14 calendars. The puzzle didn't say anything about the calendars needing to represent consecutive years. You need 7 calendars from a leap year, and 7 from a non-leap year, with the LY calendars having Jan 1st on M/T/W/H/F/S/U (and the same for the non-LY calendars).

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