[hackers] [sbase] fixed incorrect fday handling in dayofweek() function || Willem van de Krol

[git]

commit f02f2190f064584ff838352a8ec1cc92dc191742
Author: Willem van de Krol <008...@jfc.nl>
Date:   Fri Jul 4 22:23:52 2014 +0200

    fixed incorrect fday handling in dayofweek() function

diff --git a/cal.c b/cal.c
index 8faf3de..a477db9 100644
--- a/cal.c
+++ b/cal.c
@@ -79,15 +79,11 @@ drawcal(int year, int month, int day, int ncols, int nmons, 
int fday)
 static int
 dayofweek(int year, int month, int day, int fday)
 {
-       int a, y, m, d;
-
-       month++;
-       a = (14 - month) / 12;
-       y = year + 4800 - a;
-       m = month + 12 * a - 3;
-       d = (day + (153 * m + 2) / 5 + 365 * y + y / 4 - y / 100 + y \
-                       / 400 - 32045 + 1) % 7;
-       return (fday > d)? (7 - d) : (d - fday);
+       static int t[] = { 0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 };
+
+       day += 7 - fday;
+       year -= month < 2;
+       return (year + year / 4 - year / 100 + year / 400 + t[month] + day) % 7;
 }
 
 static bool