From d3628c04db9c724ee2f408f8e5eb051c74f88337 Mon Sep 17 00:00:00 2001
From: Federico Hernandez <ultrafredde@gmail.com>
Date: Tue, 23 Mar 2010 02:51:31 +0100
Subject: [PATCH] Made easter algorithm static in Date

---
 src/Date.cpp         | 52 ++++++++++++++++++++++----------------------
 src/Date.h           |  2 +-
 src/tests/date.t.cpp | 16 +++++++-------
 3 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/src/Date.cpp b/src/Date.cpp
index 4482bfc63..4cab67984 100644
--- a/src/Date.cpp
+++ b/src/Date.cpp
@@ -643,6 +643,32 @@ int Date::monthOfYear (const std::string& input)
   return -1;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+time_t Date::easter (int year)
+{
+  int Y = year;
+  int a = Y % 19;
+  int b = Y / 100;
+  int c = Y % 100;
+  int d = b / 4;
+  int e = b % 4;
+  int f = (b + 8) / 25;
+  int g = (b - f + 1) / 3;
+  int h = (19 * a + b - d - g + 15) % 30;
+  int i = c / 4;
+  int k = c % 4;
+  int L = (32 + 2 * e + 2 * i - h - k) % 7;
+  int m = (a + 11 * h + 22 * L) / 451;
+  int month = (h + L - 7 * m + 114) / 31;
+  int day = ((h + L - 7 * m + 114) % 31) + 1;
+  struct tm t = {0};
+  t.tm_isdst = -1;   // Requests that mktime determine summer time effect.
+  t.tm_mday  = day;
+  t.tm_mon   = month - 1;
+  t.tm_year  = year - 1900;
+  return mktime (&t);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 int Date::month () const
 {
@@ -964,29 +990,3 @@ bool Date::isRelativeDate (const std::string& input)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-time_t easter (int year)
-{
-  int Y = year;
-  int a = Y % 19;
-  int b = Y / 100;
-  int c = Y % 100;
-  int d = b / 4;
-  int e = b % 4;
-  int f = (b + 8) / 25;
-  int g = (b - f + 1) / 3;
-  int h = (19 * a + b - d - g + 15) % 30;
-  int i = c / 4;
-  int k = c % 4;
-  int L = (32 + 2 * e + 2 * i - h - k) % 7;
-  int m = (a + 11 * h + 22 * L) / 451;
-  int month = (h + L - 7 * m + 114) / 31;
-  int day = ((h + L - 7 * m + 114) % 31) + 1;
-  struct tm t = {0};
-  t.tm_isdst = -1;   // Requests that mktime determine summer time effect.
-  t.tm_mday  = day;
-  t.tm_mon   = month - 1;
-  t.tm_year  = year - 1900;
-  return mktime (&t);
-}
-
-////////////////////////////////////////////////////////////////////////////////
diff --git a/src/Date.h b/src/Date.h
index 72bb9f1c8..4cebb0875 100644
--- a/src/Date.h
+++ b/src/Date.h
@@ -30,7 +30,6 @@
 #include <stdio.h>
 #include <string>
 
-time_t easter (int year);
 
 class Date;
 
@@ -55,6 +54,7 @@ public:
   static bool valid (const int, const int, const int, const int, const int, const int);
   static bool valid (const int, const int, const int);
 
+  static time_t easter (int year);
   static bool leapYear (int);
   static int daysInMonth (int, int);
   static std::string monthName (int);
diff --git a/src/tests/date.t.cpp b/src/tests/date.t.cpp
index 671b3c567..15e095ccc 100644
--- a/src/tests/date.t.cpp
+++ b/src/tests/date.t.cpp
@@ -226,21 +226,21 @@ int main (int argc, char** argv)
     t.is (fromString13.second (),   56, "ctor (std::string) -> S");
 
     // Easter
-    Date e1 (easter(1980));
+    Date e1 (Date::easter(1980));
     t.is (e1.toString (), "4/6/1980", "Easter 4/6/1980");
-    Date e2 (easter(1995));
+    Date e2 (Date::easter(1995));
     t.is (e2.toString (), "4/16/1995", "Easter 4/16/1995");
-    Date e3 (easter(2000));
+    Date e3 (Date::easter(2000));
     t.is (e3.toString (), "4/23/2000", "Easter 4/23/2000");
-    Date e4 (easter(2009));
+    Date e4 (Date::easter(2009));
     t.is (e4.toString (), "4/12/2009", "Easter 4/12/2009");
-    Date e5 (easter(2010));
+    Date e5 (Date::easter(2010));
     t.is (e5.toString (), "4/4/2010", "Easter 4/4/2010");
-    Date e6 (easter(2011));
+    Date e6 (Date::easter(2011));
     t.is (e6.toString (), "4/24/2011", "Easter 4/24/2011");
-    Date e7 (easter(2012));
+    Date e7 (Date::easter(2012));
     t.is (e7.toString (), "4/8/2012", "Easter 4/8/2012");
-    Date e8 (easter(2020));
+    Date e8 (Date::easter(2020));
     t.is (e8.toString (), "4/12/2020", "Easter 4/12/2020");
 
     // Relative dates.