102 lines
2.0 KiB
C
102 lines
2.0 KiB
C
/*
|
|
* Copyright (c) 1995 Wolfram Schneider. Public domain.
|
|
*
|
|
* $Id: ostern.c,v 1.2 1996/05/10 16:29:42 ache Exp $
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
|
|
#include "calendar.h"
|
|
|
|
/* return year day for Easter */
|
|
|
|
int easter (year)
|
|
int year; /* 0 ... abcd, NOT since 1900 */
|
|
{
|
|
|
|
int e_a, e_b, e_c, e_d, e_e,e_f, e_g, e_h, e_i, e_k,
|
|
e_l, e_m, e_n, e_p, e_q;
|
|
|
|
/* silly, but it works */
|
|
e_a = year % 19;
|
|
e_b = year / 100;
|
|
e_c = year % 100;
|
|
|
|
e_d = e_b / 4;
|
|
e_e = e_b % 4;
|
|
e_f = (e_b + 8) / 25;
|
|
e_g = (e_b + 1 - e_f) / 3;
|
|
e_h = ((19 * e_a) + 15 + e_b - (e_d + e_g)) % 30;
|
|
e_i = e_c / 4;
|
|
e_k = e_c % 4;
|
|
e_l = (32 + 2 * e_e + 2 * e_i - (e_h + e_k)) % 7;
|
|
e_m = (e_a + 11 * e_h + 22 * e_l) / 451;
|
|
e_n = (e_h + e_l + 114 - (7 * e_m)) / 31;
|
|
e_p = (e_h + e_l + 114 - (7 * e_m)) % 31;
|
|
e_p = e_p + 1;
|
|
|
|
e_q = 31 + 28;
|
|
|
|
if (e_k == 0 && e_c != 0)
|
|
e_q += 1;
|
|
|
|
if (e_n == 4)
|
|
e_q += 31;
|
|
|
|
e_q += e_p;
|
|
|
|
#if DEBUG
|
|
printf("%d %d %d %d %d %d %d %d %d %d %d %d %d %d %d\n", e_a , e_b , e_c , e_d , e_e , e_f , e_g , e_h , e_i , e_k , e_l , e_m , e_n , e_p , e_q);
|
|
#endif
|
|
|
|
return (e_q);
|
|
}
|
|
|
|
/* return year day for Easter or easter depending days
|
|
* Match: Easter([+-][0-9]+)?
|
|
* e.g: Easter-2 is Good Friday (2 days before Easter)
|
|
*/
|
|
|
|
int
|
|
geteaster(s, year)
|
|
char *s;
|
|
int year;
|
|
{
|
|
register int offset = 0;
|
|
extern struct fixs neaster;
|
|
|
|
#define EASTER "easter"
|
|
#define EASTERNAMELEN (sizeof(EASTER) - 1)
|
|
|
|
if (strncasecmp(s, EASTER, EASTERNAMELEN) == 0)
|
|
s += EASTERNAMELEN;
|
|
else if ( neaster.name != NULL
|
|
&& strncasecmp(s, neaster.name, neaster.len) == 0
|
|
)
|
|
s += neaster.len;
|
|
else
|
|
return(0);
|
|
|
|
#if DEBUG
|
|
printf("%s %d %d\n", s, year, EASTERNAMELEN);
|
|
#endif
|
|
|
|
/* Easter+1 or Easter-2
|
|
* ^ ^ */
|
|
|
|
switch(*s) {
|
|
|
|
case '-':
|
|
case '+':
|
|
offset = atoi(s);
|
|
break;
|
|
|
|
default:
|
|
offset = 0;
|
|
}
|
|
|
|
return (easter(year) + offset);
|
|
}
|