# Intro CS II/spring2020/cal

< Intro CS II | spring2020Revision as of 15:13, 22 January 2020 by Robert.lowe (talk | contribs) (Created page with "<syntaxhighlight lang="cpp"> /** Computes the weekday of a given date. From Big C++ by Cay Horstmann @param year the year @param month the month (1 = January ......")

Revision as of 15:13, 22 January 2020 by Robert.lowe (talk | contribs) (Created page with "<syntaxhighlight lang="cpp"> /** Computes the weekday of a given date. From Big C++ by Cay Horstmann @param year the year @param month the month (1 = January ......")

```
/**
Computes the weekday of a given date.
From Big C++ by Cay Horstmann
@param year the year
@param month the month (1 = January ... 12 = December)
@param day the day of the month
@return the weekday (0 = Sunday ... 6 = Saturday)
*/
int day_of_week(int year, int month, int day)
{
int y = year;
int m = month - 1;
if (month < 3) { y--; m = m + 4; }
return (y + y / 4 - y / 100 + y / 400
+ 3 * m + 4 - (m - m / 8) / 2 + day) % 7;
}
```