Determination of Day of Week of a Date

ARISTEAN
CALENDAR

DETERMINATION OF THE DAY OF THE WEEK

Month number in the quarter	1	2	3
Maximum number of days in month*	31	30	30
First Quarter	Jan	Feb	Mar
Second Quarter	Apr	May	Jun
Third Quarter	Jul	Aug	Sep
Fourth Quarter	Oct	Nov	Dec
Constant to be added to date	0	3	5

*Exceptions are December 31 which is World Peace Day or Grand Sabbath and June 31 which is Leap Year Day or Glorious Sabbath. Both these dates do not have the regular name day of the week.

1.	Determine which month of the quarter the date belongs to. Example: August is the second month of the quarter.
2.	Add the constant to the date to get the sum. Note that the constant to be added is the number of blank spaces before the first day of the month in question in the calendar. Example: August 22. Constant for August is 3 since it is the second month of the quarter. Hence, add 3 to 22. Sum is 25.
3.	Divide the sum by 7 and find the remainder. The remainder determines the day of the week.

If remainder is	1	2	3	4	5	6	0
The day is	Mon	Tue	Wed	Thu	Fri	Sat	Sun

Sample illustrations:

1.	April 15	April is the first month of the quarter, hence, 0 is added to 15 to give a total of 15. 15 is divided by 7 gives 2 remainder 1. Hence, April 15 is Monday.
2.	August 22	August is the second month of the quarter, so 3 has to be added to the date giving a total of 25. Divide 25 by 7. The answer is 3, remainder 4. Hence, August 22 is Thursday.
3.	June 9	June is the third month of the quarter. Therefore, add 5 to 9 giving 14. Divide 14 by 7 gives 2 with 0 remainder. Hence, June 9 is Sunday.