문자열형 날자&시간을 1초씩 증가시키는 방법.

#include <time.h>
#include <string.h>
#include <stdio.h>
 
int main()
{
    struct tm   tm_time;
    bzero( &tm_time, sizeof( tm_time ) );
    tm_time.tm_sec = 59;
    tm_time.tm_min = 59;
    tm_time.tm_hour = 23;
    tm_time.tm_mday = 31;
    tm_time.tm_mon = 11;
    tm_time.tm_year = 2008-1900;
    time_t t_t = mktime( &tm_time );
 
    struct tm * t1 = localtime( &t_t );
    printf( "%04d%02d%02d %02d%02d%02d\n",
            t1->tm_year + 1900, t1->tm_mon + 1, t1->tm_mday,
            t1->tm_hour, t1->tm_min, t1->tm_sec );
 
    ++t_t;
 
    t1 = localtime( &t_t );
    printf( "%04d%02d%02d %02d%02d%02d\n",
            t1->tm_year + 1900, t1->tm_mon + 1, t1->tm_mday,
            t1->tm_hour, t1->tm_min, t1->tm_sec );
 
    return 0;
}

출력.
 
20081231 235959
20090101 000000