Transfer from small fish
Recently, some people saw that someone asked the week algorithm, especially organized, these algorithms were searching from online, and the implementation of the algorithm was written in the project. I hope to be helpful.
One: Common formula W = [Y-1] [(Y-1) / 4] - [(Y-1) / 100] [(Y-1) / 400] D
Y Y is the number of years, D is the cumulative day of this day in this year, that is, this day is the first day this year.
2: Zeller formula
W = Y [Y / 4] [C / 4] -2C [26 (M 1) / 10] D-1
The symbols in the formula are as follows, W: Week; C: Century; Y: Year (two digits); M: Month (M is greater than or equal to 3, less than or equal to 14, in the Caile formula, 1, 2 The month should be considered as a previous year to calculate. For example, January 1, 2003 is considered to be calculated on March 1, 2002); D: Japan; [] Represents Fix, ie .
The Zeller formula greatly reduces the computational complexity compared to the general general calculation formula.
Three: Improvements to the Zeller formula
Author: Cong Feng think in terms compared to other common generic formula, Zeller (Zeller) formula greatly reduces the computational complexity. However, the general-purpose calculation formula given by the author seems to be more simple (including the operation process). The formula is now listed below: w = [Y / 4] R (Y / 7) -2R (C / 4) m ' D
The symbols in the formula are as follows, and R () represents the payment, that is, as long as the remaining number; M 'is the correction number of M, it is now given from 1 to December 1' to 12 'below: (1', 10 ') ) = 6; (2 ', 3') = 2; (4 ', 7') = 5; 5 '= 0; 6' = 3; 8 '= 1; (9', 12 ') = 4 (Note: In the formula given by the author, Y is 1 '= 5; 2' = 1). Other symbols are the same as the meaning of the Zeller formula.
Four: Kelason Calculation Formula
The name of this formula is named, haha, I hope everyone should not see it.
W = (D 2 * m 3 * (M 1) / 5 y y / 4-y / 100 y / 400) MOD 7
In the formula, D represents the number of days in the date, and m represents the number of months, y indicates the number of years.
Note: There is a place different from other formulas in the formula:
Despect in January and February as the last year of the last year of the last year, the example: If it is 2004-10, it is converted to: 2003-13-10 to enter the formula calculation.
to sum up:
These algorithms have characteristics, as for the specific calculation process of the formula, because the reason is not listed here, if necessary, leave the email address, I will send it to you.
Posted on August 09, 2004 9:59 AM
