more on 19

ewilson · Jan 29, 2011 · 8712697 · 8712697
1 parent 610c82e
commit 8712697
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/019.hs b/019.hs
@@ -28,3 +28,9 @@ daysInMonth date
 		where 
 			m = month date
 			y = year date
+
+dayShiftFromYearChange :: Year -> Year -> Int
+dayShiftFromYearChange start end = mod7 (sum $ map daysInYear [start..end-1])
+
+mod7 :: Int -> Int
+mod7 n = mod n 7