static inline int UpdateToYMDYear(const int base_year, const struct tm *time)
{
int year = time->tm_year;
if (base_year < -2100)
{
const int diff = year - 2100;
year = abs(base_year) - diff;
}
if (base_year < -1900)
{
year *= -1;
}
else if (base_year >= 0 && base_year < 100)
{
year -= 1900;
}
else if (base_year < 0)
{
const int org_base_year = NormalizeYMDYear(-1 * base_year);
year = base_year - (org_base_year - year);
}
return year;
}
static void YMD_TO_TM(const YMD *ymd, struct tm *time, bool *leap_added)
{
time->tm_year = NormalizeYMDYear(ymd->year);
time->tm_mon = ymd->mon;
time->tm_wday = ymd->wday;
time->tm_mday = ymd->mday;
int t = ymd->time;
t /= DateTimeTicks_PerSecond; // discard ms
time->tm_sec = t % 60;
t /= 60;
time->tm_min = t % 60;
t /= 60;
time->tm_hour = t;
// mktime etc. broken-out time accepts 1900 as a start year while epoch is 1970
// temporarily add a calendar day for leap pass
bool leap_year = IsLeap(time->tm_year);
*leap_added = false;
if (ymd->yday == 60 && leap_year) {
time->tm_mday++;
*leap_added = true;
}
}
// Windows DateTime implementation normalizes the year beyond <1900 >2100
// mktime etc. broken-out time bases 1900
static inline int NormalizeYMDYear(const int base_year)
{
int retval = base_year;
if (base_year < -2100)
{
retval = 2100;
}
else if (base_year < -1900)
{
retval = base_year * -1;
}
else if (base_year >= 0 && base_year < 100)
{
retval = 1900 + base_year;
}
else if (base_year < 0)
{
retval = NormalizeYMDYear(-1 * base_year);
}
return retval;
}
