Example #1

When Year Value = 0

September 21, 2014

1)    Month Value = 1

2)    Day of Month Value = 0

            21-21 (or 7x3) = 0

3)    Year Value = 0

                A)   14/4 = 3 (discard remainder of 2)

                B)    14 -14 (or 7 x 2) = 0

                C)    Century Code = 4

        A+B+C = 3 + 0 + 4 = 7

           7 - 7 = 0  

( 2014 year value will always = 0 )

 **Note that, in this example, the year value for 2014 equals 0.  This means that for any date in 2014, you could skip the year value calculation, and the month plus day values alone could determine the day of the week.

Total:  1 + 0 + 0 = 1

      1 = Sunday

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Example #2

When Month Value + Day Value = 0

November 8, 2017

1)    Month Value =6

2)    Day of Month Value = 1

                   8 - 7 (or 7x1) = 1

**Note that, in this example, the month value plus the  day value equals 7.  We could now subtract 7 to have a month plus day value of 0.  This means that the resulting year value is the only number we would now need to consider, and that number alone could determine the day of the week in this case.

3)    Year Value = 4

                A)   17/4 = 4 (discard remainder of 1)

                B)    17 -14 (or 7 x 2) = 3

                C)    Century Code = 4

        A+B+C = 4 + 3 + 4 = 11

           11 - 7 = 4

( 2017 year value will always = 4 )

Total:  6 + 1 + 4 = 11 

              11 - 7 = 4

        4 = Wednesday

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Example #3

Leap Year Calculation

February 3, 2016

1)    Month Value = 5**

                6 - 1 (for Leap Year) = 5

2)    Day of Month Value = 3

3)    Year Value =3

                A)   16/4 = 4  (no remainder to discard)**

                B)    16 -14 (or 7 x 2) = 2

                C)    Century Code = 4 

        A+B+C = 4 + 2 + 4 = 10

           10 - 7 = 3

( 2016 year value will always = 3 )

 **Note that, in this example, the two digit year value (16) is a multiple of 4, with no remainder.  This means that this is a Leap Year, so you must subtract 1 from the month value for any calculations involving the months of January or February (other months are unaffected).

Total:  5 + 3 + 3 = 11

       11 - 7 = 4

       4 = Wednesday

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                        Key:

Month Values

January = 3

February = 6

March = 6

April = 2

May = 4

June = 0

July = 2

August = 5

September = 1

October = 3

November = 6

December = 1

Century Values

1700s = 2

1800s = 0

1900s = 5

2000s = 4

2100s = 2

Day of Week Values 

 Sunday = 1 

Monday = 2 

Tuesday = 3 

Wednesday = 4 

Thursday = 5 

Friday = 6 

Saturday = 0