What Day of the Week
The Day of the Week born, calculation of the first day of the week year of the week and day of the year:
How to calculate the day of the week you were born, or how to get the day or date within the year 2009 week calendar? Here a how to calendar tutorial, which will show you to find out each day, week or month in the year 2009.
First of all you will need the correct month and date to begin the week day calculation …
What day of the week?
How to determine the day of the week, given the month, day and year. Usually you will need this calculation to get day of the week born, day of the year or year of the week.
Day of the Week calculation
Here is a standard method suitable for mental computation:
- You have to take the last two digits of the given year.
- Divide by 4, discarding any fraction.
- Add the day of the month.
- Add the month’s key value: JFM AMJ JAS OND 144 025 036 146
- Subtract 1 for January or February of a leap year.
- For a Gregorian date, add 0 for 1900′s, 6 for 2000′s, 4 for 1700′s, 2 for 1800′s; for other years, add or subtract multiples of 400.
- For a Julian date, add 1 for 1700′s, and 1 for every additional century you go back.
- Add the last two digits of the year.
- Divide by 7 and take the remainder.
- Now 1 is Sunday, the first day of the week, 2 is Monday, and so on.
Other Day of the week formula and calculation methods
Babwani’s formula for week calculation
Babwani’s method of finding the weekday was originally published the first time in The Mathematical Gazette, London 2004. He has discovered an alternative formula which facilitates the use of date and also allow to find each day, week, month and year when the other information is existent.
Zeller algorithm for date calcualtion
The Zeller algorithm has numbered the months from 3 for March to 14 for February. Helping construct is that the year is assumed to begin in March; in an examplaric date calculation February 2010 is to be assumed as month 14 of 2009.
