86 lines
1.9 KiB
C
86 lines
1.9 KiB
C
#include <math.h>
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#include <stdio.h>
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#include <time.h>
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int main() {
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time_t cur_time, start, start_gmt, now, now_gmt;
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struct tm *gmt, mt;
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long int offset;
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double diff, part, days, hours, lon, lst;
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int i;
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cur_time = time(NULL);
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printf("Time = %ld\n", cur_time);
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gmt = gmtime(&cur_time);
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printf("GMT = %d/%d/%2d %d:%02d:%02d\n",
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gmt->tm_mon, gmt->tm_mday, gmt->tm_year,
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gmt->tm_hour, gmt->tm_min, gmt->tm_sec);
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mt.tm_mon = 2;
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mt.tm_mday = 21;
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mt.tm_year = 98;
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mt.tm_hour = 12;
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mt.tm_min = 0;
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mt.tm_sec = 0;
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start = mktime(&mt);
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offset = -(timezone / 3600 - daylight);
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printf("Raw time zone offset = %ld\n", timezone);
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printf("Daylight Savings = %d\n", daylight);
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printf("Local hours from GMT = %d\n", offset);
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start_gmt = start - timezone + (daylight * 3600);
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printf("March 21 noon (CST) = %ld\n", start);
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printf("March 21 noon (GMT) = %ld\n", start_gmt);
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for ( i = 0; i < 12; i++ ) {
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mt.tm_mon = i;
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mt.tm_mday = 21;
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mt.tm_year = gmt->tm_year;
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mt.tm_hour = 12;
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mt.tm_min = 0;
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mt.tm_sec = 0;
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now = mktime(&mt);
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offset = -(timezone / 3600 - daylight);
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printf("Raw time zone offset = %ld\n", timezone);
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printf("Daylight Savings = %d\n", daylight);
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printf("Local hours from GMT = %d\n", offset);
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now_gmt = now - timezone + (daylight * 3600);
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printf("%d/%d/%d noon (CST) = %ld\n", i+1, 21, 97, now);
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printf("%d/%d/%d noon (GMT) = %ld\n", i+1, 21, 97, now_gmt);
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diff = (now_gmt - start_gmt) / (3600.0 * 24.0);
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printf("Time since 3/21/%2d GMT = %.2f\n", gmt->tm_year, diff);
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part = fmod(diff, 1.0);
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days = diff - part;
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/* hours = gmt->tm_hour + gmt->tm_min/60.0 + gmt->tm_sec/3600.0; */
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hours = 12;
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lon = -112;
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lst = (days + lon)/15.0 + hours - 12;
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while ( lst < 0.0 ) {
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lst += 24.0;
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}
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printf("days = %.1f hours = %.2f lon = %.2f lst = %.2f\n",
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days, hours, lon, lst);
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}
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return(0);
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}
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