Instructions

Example:
November 12, 2070

Step 1: Determine the code for the century:
Century:

1800’s

1900’s

2000’s

2100’s

Code #

2

0

6

4


Century = 2000’s
The code for 2000’s is 6
Total = 6

Step 2: Determine the code for the year:
Year:

00

04

08

12

16

20

24

28

32

36

40

44

48

52

56

60

64

68

72

76

80

84

88

92

96


Code #

1

6

4

2

0

5

3


Year = 70
68 is 2, so 69 is 3 and 70 is 4!
Total = 10 (6 + 4)

Step 3: Determine month code:
Jan = 6 
Feb = 2 
Mar = 2 
Apr = 5 
May = 0 
Jun = 3 
Jul = 5 
Aug = 1 
Sep = 4 
Oct = 6 
Nov = 2 
Dec = 4 

Month = November
November = 2
Total = 12 (6 + 4 + 2)

Step 4: Determine date code:
Date:


1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31


Code #

0

1

2

3

4

5

6

TIP:
Keep subtracting 7
or multiples from the totals, as you progress – to make it easier,
instead of waiting till the end!
You may also use 1 or 2 for 6 or 5 etc. to reach the same result finally.

Date = 12
The code for date:12 is 5.
Total = 17(6 + 4 + 2 + 5)
Shortcut #1: Subtract 7, 14,
21 or 28, from the date to find code, dates less than 7 are already equal to
the code.
Example:
Nov 12: 12  7 = 5.
Example:
Nov 26: 26  21 = 5
Shortcut #2: Simply add the
date to the total. Example: Nov 12: Code=12, Total = 24 (6 + 4 + 2
+ 12).

Step 5: Determine dayofweek from total
Divide the total from Step 3 by seven, the remainder giving the dayofweek:
Dayofweek:

Sun

Mon

Tue

Wed

Thu

Fri

Sat

Remainder:

0

1

2

3

4

5

6


Total = 17
(Century=6, Year=4, Month=2, Date=5)
17 divided by 7 is:
2 remainder 3
3
= Wednesday

Step 6: Don’t
forget leapyear!
Subtract 1 at any point in the process only if the year is a leap year
provided the month is January or February – not for other months!
(Shortcut: As a
last step, you can simply take the day before if the year is a leap year, and
the month is Jan. or Feb.)
LeapYear Rules
Since 1582 (1752 in USA and other years in other
countries), the following is the currently widelyunknown leapyear rule:
A year is a leapyear if it is evenly divisible by 4 unless it is evenly divisible by 100, UNLESS it is evenly divisible by 400. This means that
1800, 1900, and 2100 are NOT leap years, but 2000 IS a leap year, since it is
evenly divisible by 400!

2070 is not a leap year.
Shortcut #1: The year is a
leap year if it is found in the table in step 1. (68 and 72 are leap years,
but 70 is not)
Shortcut #2: A year is a leap
year if it is evenly divisible by 4.
