How to Know the Day of the Week for Any Day of Any Year

Step-by-Step Guide

1. 1

   Step 1: Find the sum of the "basic numbers" substituted for Day

   Take 22nd October 2010, for example.
   
   For date 22 base number is 1, for October also it is 1, for year 10 it is
   4.
   
   For the century it is 21 divided by 4 and the remainder is 1, and the basic number for that is
   6.
   
   These all add up to
   12.
   
   Basic number 0 for
   -- Dates
   -- 07, 14, 21, 28;
   -- Months-- April, July;
   -- Years
   --01, 07, 18, 24, 29, 35, 46, 52, 57, 63, 74, 80, 85, 91;
   -- Remainder
   --
   0.
   
   Basic number 1 for
   - Dates
   -- 01, 08, 15, 22, 29;
   -- Months
   --January, October;
   -- Years
   -- 02, 08, 13, 19, 30, 36, 41, 47, 58, 64, 69, 75, 86, 92,
   97.
   
   Basic Number 2 for
   -- Dates
   -- 02, 09, 16, 23, 30;
   -- Month
   -- May;
   -- Years
   -- 03, 14, 20, 25, 31, 42, 48, 53, 59, 70, 76, 81, 87, 98;
   --Remainder
   --
   3.
   
   Basic number 3 for
   - Dates
   -- 03, 10, 17, 24, 31;
   -- Month
   -- August;
   -- Years
   --04, 09, 15, 26, 32, 37, 43, 54, 60, 65, 71, 82, 88, 93,
   99.
   
   Basic number 4 for
   -- Dates
   -- 04, 11, 18, 25;
   -- Months
   -- February, March, November;
   -- Years
   --10, 16, 21, 27, 38, 44, 49, 55, 66, 72, 77, 83, 94, 00;
   -- Remainder
   --
   2.
   
   Basic number 5 for
   -- Dates
   -- 05, 12, 19, 26;
   -- Month
   -- June;
   -- Years
   -- 05, 11, 22, 28, 33, 39, 50, 56, 61, 67, 78, 84, 89,
   95. .
   - Basic number 6 for
   -- Dates
   -- 06, 13, 20, 27;
   -- Months
   -- September, December;
   -- Years
   -- 06, 12, 17, 23, 34, 40, 45, 51, 62, 68, 73, 79, 90, 96;
   -- Remainder
   --
   1.
   
   In leap years add ‘1’ in months March to December.
   
   For years ‘00’ leap year only if the century divides exactly by 4, i.e. remainder is
   0. , If remainder is 0 – Sunday; 1 – Monday; 2 – Tuesday; 3 – Wednesday; 4
   -Thursday; 5 – Friday; 6 – Saturday.
   
   Examples:
   1.1.2007
   ---- 1 + 1 + 0 + 6 + 0 = 8, remainder after dividing by 7 is 1 so it is Monday.
   9.3.2008
   ---- 2 + 4 + 1 + 6 + 1 = 14, remainder after dividing by 7 is 0 so it is Sunday.
   31.12.2000
   ----- 3 + 6 + 4 + 0 + 1 = 14, remainder after dividing by 7 is 0 so it is Sunday.
   1.1.2001
   ----1 + 1 + 0 + 6 + 0 = 8, remainder after dividing by 7 is 1 so it is Monday.
   21.11.1763
   ---- 0 + 4 + 0 + 4 + 0 = 8, remainder after dividing by 7 is 1 so it is Monday.
   1.3.1848
   ---- 1+ 4 + 2 + 2 + 1 = 10, remainder after dividing by 7 is 3 so it is Wednesday.
   2.1.1976
   ---- 2 + 1 + 2 + 0 + 0 = 5, remainder after dividing by 7 is 5 so it is Friday.
   25.6.2492
   ---- 4 + 5 + 1 + 6 + 1 = 17, remainder after dividing by 7 is 3 so it is Wednesday.
   13.11.4567
   ---- 4 + 4 + 5 + 4 + 0 = 17 remainder after dividing by 7 is 3 so it is Wednesday. , Our ancestors, as such relied on the Sun and moon for their measurement of TIME.
2. 2

   Step 2: Remainder left after dividing Century by 4

   The coming of the full Moon periodically was a second measure of time.
   
   The changing seasons and their recurrence was a third measure of time.
   
   Different Nations had their own notions of measurement of time, but the most prevalent one today is the Gregorian Calendar, which has taken its definition of a year from the time taken by the Earth to revolve once round the Sun and each minute consisting of 60 seconds. , The number of months had their origin from the number of Gods in ancient Greek mythology.
   
   These months were further sub-divided into days, the day itself being measured by the time taken by the Earth to rotate once around its axis.
   
   The days were further sub-divided, in this conception of time, into 24 hours, each hour consisting of 60 minutes.
   
   For convenience, the days were grouped into what we call Weeks.
   
   Perhaps people wanted to take time off from their hard work and also wanted to keep aside some time for their spiritual well-being.
   
   The week thus came to be divided into seven days, Sunday being, generally, considered a day of rest and set aside amongst Christians for Mass Prayers.
   
   Other religions too have, in general, one day set aside for prayers. , A normal year consists of 365 days, with leap year having 366 days.
   
   This adjustment was, however, not enough and a further adjustment required that there should be no leap year every 100th year, but again every 400th year has to be a leap year to keep the timing in tune with the rotation of Earth. , From this arises the need for a perpetual calendar, which will meet the needs of people for all times to come. , If we start from 1st January of a particular year, we find that the day on 1st February will differ from the day in January by three.
   
   The day on 1st March, other than in Leap year, will be the same as on 1st February.
   
   The day on 1st April will be three more than that on March and so on.
   
   From this, we get the first clue for our calculations. , Therefore, 1st January of the next year will be different from the previous year by one, except in the leap year when it will differ by
   2.
   
   This gives us the second clue for our calculations. , This, along with the fact that the year ‘00’ will be a leap year only once in four times, gives us our third and practically the final clue for our calculations. , Here is the final results.
   
   Let us assign one number to each day of the week for convenience, we will start with Sunday as number Zero, Monday as One and so on. ,,,,
   1. 1901 to
   31.
   12. 2000 etc.------ ,
3. 3

   Step 3: and Leap Year.

4. 4

   Step 4: Divide the sum by 7.

5. 5

   Step 5: In this ever-changing world

6. 6

   Step 6: only the Sun and the Moon and a few Planets can be said to have some permanency.

7. 7

   Step 7: The rotation of the Earth around the Sun

8. 8

   Step 8: the dawn of the morning

9. 9

   Step 9: the coming of the night

10. 10

    Step 10: were the first measurements of time.

11. 11

    Step 11: The year was further divided into months.

12. 12

    Step 12: The time taken by the earth to complete one revolution round the Sun

13. 13

    Step 13: in our current Unit

14. 14

    Step 14: is odd and not totally accurate

15. 15

    Step 15: thus arose the leap year every 4th year.

16. 16

    Step 16: Now dividing 365 days by 12 leaves a balance and due to this

17. 17

    Step 17: there was unevenness in the number of days in a month and again the number of weeks does not divide the month and the year fully and as such it is difficult to say exactly what day of the week will fall in a particular month.

18. 18

    Step 18: To construct such a calendar

19. 19

    Step 19: look back upon how we defined our months and years.

20. 20

    Step 20: 52x7 = 364.

21. 21

    Step 21: The 29th day in February changes our calculations

22. 22

    Step 22: from the month of March onwards in the leap year and permanently for all other years.

23. 23

    Step 23: Starting from the 1st January of any one year and knowing the day in that month

24. 24

    Step 24: we can thus prepare the frame work of our perpetual calendar without going into further details.

25. 25

    Step 25: For January

26. 26

    Step 26: given the number 1

27. 27

    Step 27: for February the number 4 (in view of what is explained earlier in clue (1))

28. 28

    Step 28: March number 4

29. 29

    Step 29: April number 0 (instead of 7 as division by 7 leaves remainder zero and we have 7 days in a week)

30. 30

    Step 30: May number 2

31. 31

    Step 31: and so on.

32. 32

    Step 32: For working out the day of the week for any date we will have to add the base numbers for –) as given in the WORKING CHART given below

33. 33

    Step 33: except that when the total is more than 6 we will have to divide by 7 and take the remainder:

34. 34

    Step 34: First Basic Number is given

35. 35

    Step 35: thereafter Date

36. 36

    Step 36: Month Calender years are to be taken for that number

37. 37

    Step 37: then months

38. 38

    Step 38: then days and then Remainder after dividing by 4 - called Remainder.------

39. 39

    Step 39: Please Note ---- Century counts from 1.

40. 40

    Step 40: You may need to add basic numbers for Date

41. 41

    Step 41: Months

42. 42

    Step 42: Century.

Detailed Guide

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