Thread: Printing System time and 30 minute alarm

well this is what i got and the code compiles but and gives me the current time and then gives me an error and boots out.

Code:

{
    time_t t1;                                 
    struct tm *tptr;
    clock_t ticks;                             
    char *s;
    struct tm *ntptr;

    if ( ( t1 = time(( time_t * ) 0 )) != ( time_t )-1 ) 
	{
        s = ctime( &t1 );
        printf( "Current time is %s", s );
        tptr = localtime( &t1 );
        ntptr->tm_min = mktime(tptr->tm_min += 30);
        printf( "You have an appointment in 30 minutes at time %d:%d:%d.\n",              
                                       ntptr->tm_hour, 
                                       ntptr->tm_min,          
                                       ntptr->tm_sec );
      
       }
    else
        printf( "Error with the time() function\n" );

                                                          
    
    return 0;
}