#include <time.h> static int mday[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; struct tm *localtime(const time_t *tp){	time_t t = *tp;	static struct tm tm;		tm.tm_sec = t % 60;	t /= 60;	tm.tm_min = t % 60;	t /= 60;	tm.tm_hour = t % 24;	t /= 24;	tm.tm_wday = (t + 4) % 7;  // Jan 1 1970 = Thursday		int isleap = 0;	for (tm.tm_year=70;; tm.tm_year++) {		isleap = (tm.tm_year+1900)%4 == 0;		if (t < 365 + isleap)			break;		t -= 365 + isleap;	}		tm.tm_yday = t;	for (tm.tm_mon=0;; tm.tm_mon++) {		isleap = (tm.tm_year+1900)%4 == 0 && tm.tm_mon == 1;		if (t < mday[tm.tm_mon] + isleap)			break;		t -= mday[tm.tm_mon] + isleap;	}	tm.tm_mday = t + 1;	tm.tm_isdst = 0; 	return &tm;} struct tm *gmtime(const time_t *tp){	return localtime(tp);}