2 * Copyright (C) 1993-1996 by Andrey A. Chernov, Moscow, Russia.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 * $FreeBSD: src/usr.bin/calendar/paskha.c,v 1.4.10.2 2002/05/27 12:14:46 dwmalone Exp $
27 * $DragonFly: src/usr.bin/calendar/paskha.c,v 1.4 2006/09/16 18:38:00 pavalos Exp $
37 #define PASKHA "paskha"
38 #define PASKHALEN (sizeof(PASKHA) - 1)
41 extern struct fixs npaskha;
43 static int paskha(int);
45 /* return year day for Orthodox Easter using Gauss formula */
46 /* (old style result) */
60 e = (2*b + 4*c + 6*d + y) % 7;
61 return(((cumdays[3] + 1) + 22) + (d + e));
64 /* return year day for Orthodox Easter depending days */
67 getpaskha(char *s, int year)
71 if (strncasecmp(s, PASKHA, PASKHALEN) == 0)
73 else if (npaskha.name != NULL
74 && strncasecmp(s, npaskha.name, npaskha.len) == 0
81 /* Paskha+1 or Paskha-2
95 return(paskha(year) + offset + 13/* new style */);