unixtodos

#include

#include

char *month[] = {"---", "Jan", "Feb", "Mar", "Apr", "May", "Jun","Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

#define SECONDS_PER_DAY 86400L /* the number of seconds in one day */

struct date dt;

struct time tm;

int main(void)

{

unsigned long val;

/* get today's date and time */

getdate(&dt);

gettime(&tm);

printf("today is %d %s %d\n", dt.da_day, month[dt.da_mon], dt.da_year);

/* convert date and time to unix format (number of seconds since Jan 1, 1970) */

val = dostounix(&dt, &tm);

/* subtract 42 days worth of seconds */

val -= (SECONDS_PER_DAY * 42);

/* convert back to dos time and date */

unixtodos(val, &dt, &tm);

printf("42 days ago it was %d %s %d\n",dt.da_day, month[dt.da_mon], dt.da_year);

return 0;

}