/* Convert MSDOS packed time to long seconds since 1970. (Basic conversion
derived from code supplied by Stuart Gathman.) */

long
dos2sec(dostime,dosdate)
unsigned dostime,dosdate;
{
int y,dayofyear;
long time;

#define Uyear ((dosdate >> 9) & 0x3f)		/* as stored in search */
#define Umonth ((dosdate >> 5) & 0x0f)		/* first/next structure */
#define Uday (dosdate & 0x1f)			/* or get file time DOS call */
#define Uhour ((dostime >> 11) & 0x1f)
#define Uminute ((dostime >> 5) & 0x3f)
#define Usecond ((dostime & 0x1f) << 1)		/* (kept as 2 second resolution) */

	y= Uyear + 80; 				/* DOS date base is 1980 */
	dayofyear= Uday + ((Umonth * 275) / 9) - 30;/* day of year, */
	if (Umonth > 2) {			/* handle leapyears */
		--dayofyear;			/* Feb 28/29, 1 Mar */
		if (Uyear % 4) --dayofyear;
	}
	time= dayofyear + ((long)(y - 1) * 1461L) / 4; /* day of century */

	time -= 25203L;				/* minus days 1900 - 1970 */

	time *= 86400L;				/* second of century */
	time += (long)Uhour * 3600L;		/* add seconds this day, */
	time += Uminute * 60;
	time += Usecond;
/*	cprintf("dos2sec: %02d/%02d/%02d %02d:%02d:%02d=%lu\r\n",y,Umonth,Uday,Uhour,Uminute,Usecond,time);
*/	return(time);
}

/* Convert seconds since 1970 to MSDOS packed time and date. The DOS date is
in the upper two bytes, time in the lower. (Same as passed in a TELINK 
block.) (Basic conversion derived from code supplied by Stuart Gathman.) */

long
sec2dos(sec70)
long sec70;
{
long time;
int dayofyear,leapyear;
int year,month,day;

	time= sec70 % 86400L;			/* time only */
	sec70 /= 86400L;			/* date only */
	sec70 += 25203L;			/* add days 1900 - 1970 */
	leapyear= 2;

	year= ((sec70 - (sec70 / 1461) + 364) / 365);	/* make year, */
	dayofyear= sec70 - ((long)(year - 1) * 1461) / 4;/* day in current year */
	if (year % 4 == 0) leapyear= 1;
	if (dayofyear > 59 && ((dayofyear > 60) || (leapyear == 2)))
		dayofyear += leapyear;
	month= (269 + (dayofyear * 9)) / 275;
	day= dayofyear + 30 - ((275 * month) / 9);

/*	cprintf("\r\nsec2dos: %lu == %02d/%02d/%02d %02d:%02d:%02d\r\n",x,year,month,day,time / 3600L,(time % 3600L) / 60L,(time % 3600L) % 60L);
*/
	sec70= 0L;
	sec70 |= ((year - 80) & 0x3f) << 9;	/* pack the date (starts 1980) */
	sec70 |= (month & 0x0f) << 5;		/* into lower 16 bits */
	sec70 |= day & 0x1f;
	sec70 <<= 16L;				/* shift to upper 16 bits */

	sec70 |= ((time / 3600L) & 0x1f) << 11;	/* then pack the time */
	time %= 3600L;				/* hours, */
	sec70 |= (time / 60L) << 5;		/* minutes, */
	sec70 |= (time % 60L) >> 1;		/* seconds. */
	return(sec70);
}