From abb29b0b113102a7dea3e4691a853ee20e30f614 Mon Sep 17 00:00:00 2001
From: daurnimator <quae@daurnimator.com>
Date: Wed, 24 Jul 2013 11:52:27 -0400
Subject: [PATCH 1/1] src/timetable: Break out leap_years_since function from
 doomsday

---
 src/timetable.lua | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/timetable.lua b/src/timetable.lua
index c71c59b..b58ad0f 100644
--- a/src/timetable.lua
+++ b/src/timetable.lua
@@ -27,9 +27,13 @@ local function month_length ( m , y )
 	end
 end
 
+local function leap_years_since ( year )
+	return idiv ( year , 4 ) - idiv ( year , 100 ) + idiv ( year , 400 )
+end
+
 local function doomsday ( year )
 	return ( 3 -- Tuesday
-		- 1 + year + idiv ( year , 4 ) - idiv ( year , 100 ) + idiv ( year , 400 ) )
+		- 1 + year + leap_years_since ( year ) )
 		% 7 + 1
 end
 local doomsday_cache = setmetatable ( { } , {
-- 
2.39.5