/* *  linux/kernel/mktime.c * *  (C) 1991  Linus Torvalds */#include <time.h>/* * This isn't the library routine, it is only used in the kernel. * as such, we don't care about years<1970 etc, but assume everything * is ok. Similarly, TZ etc is happily ignored. We just do everything * as easily as possible. Let's find something public for the library * routines (although I think minix times is public). *//* * PS. I hate whoever though up the year 1970 - couldn't they have gotten * a leap-year instead? I also hate Gregorius, pope or no. I'm grumpy. */#define MINUTE 60#define HOUR (60*MINUTE)#define DAY (24*HOUR)#define YEAR (365*DAY)/* interestingly, we assume leap-years */static int month[12] = {	0,	DAY*(31),	DAY*(31+29),	DAY*(31+29+31),	DAY*(31+29+31+30),	DAY*(31+29+31+30+31),	DAY*(31+29+31+30+31+30),	DAY*(31+29+31+30+31+30+31),	DAY*(31+29+31+30+31+30+31+31),	DAY*(31+29+31+30+31+30+31+31+30),	DAY*(31+29+31+30+31+30+31+31+30+31),	DAY*(31+29+31+30+31+30+31+31+30+31+30)};long kernel_mktime(struct tm * tm){	long res;	int year;	year = tm->tm_year - 70;/* magic offsets (y+1) needed to get leapyears right.*/	res = YEAR*year + DAY*((year+1)/4);	res += month[tm->tm_mon];/* and (y+2) here. If it wasn't a leap-year, we have to adjust */	if (tm->tm_mon>1 && ((year+2)%4))		res -= DAY;	res += DAY*(tm->tm_mday-1);	res += HOUR*tm->tm_hour;	res += MINUTE*tm->tm_min;	res += tm->tm_sec;	return res;}