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authorPixel <Pixel>2002-08-20 07:42:21 +0000
committerPixel <Pixel>2002-08-20 07:42:21 +0000
commit1b0a5db816b7610c83615e93095155b1709f55da (patch)
tree6ad2f121c493131e679367933bf07440ec680d43 /generic/datecalc.c
parent396239cc78a75ba7be739788485319c92b07d827 (diff)
Whoops
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+/* datedif - calculates the difference in days between two dates
+ * Copyright (C) 2000 Micael Widell contact: xeniac@linux.nu
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <time.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Gaus's formula - days since 1.3.1600 (Gregorian calendar) */
+int days(register int n, register int m, register int y)
+{
+ register int cy;
+ if((m -= 2) <= 0){
+ m += 12; y--;
+ }
+ y -= 1600; cy = y/100;
+ return 365*y+y/4-cy+cy/4+367*m/12+n-31;
+}
+
+
+double dateCalc(char * date1, char * date2){
+
+ /* Declare the needed variables */
+ char* date[2];
+ struct tm *date_tm[2];
+ time_t date_time_t[2];
+ double dateDifference;
+ int isToday[2] = { 0, 0 };
+ char buffer[5];
+ int day[2], month[2], year[2], i;
+
+ date[0] = date1;
+ date[1] = date2;
+
+ /* If any of the arguments are "today", then include today's date in the
+ right variables */
+ for(i = 0; i < 2; i++){
+ if(!strcmp(date[i], "today")){
+ time(&date_time_t[i]);
+ date_tm[i] = localtime(&date_time_t[i]);
+ day[i] = (*date_tm[i]).tm_mday;
+ month[i] = (*date_tm[i]).tm_mon + 1;
+ year[i] = (*date_tm[i]).tm_year + 1900;
+ isToday[i] = 1;
+ }
+ }
+
+ /* Cut out the year, month and day from 8-digit datestrings */
+ for (i = 0; i < 2; i++){
+ if(!isToday[i]){
+ memset(buffer, 0, 5);
+ strncpy(buffer, &date[i][6], 2);
+ day[i] = atoi(buffer);
+ strncpy(buffer, &date[i][4], 2);
+ month[i] = atoi(buffer);
+ strncpy(buffer, date[i], 4);
+ year[i] = atoi(buffer);
+ }
+ }
+
+ /* Calculate the difference */
+ dateDifference = days(day[1], month[1], year[1]) - days(day[0], month[0], year[0]);
+
+ return dateDifference;
+}