函数名: stime 
 功  能: 设置时间 
 用  法: #include <time.h> 
         int stime(long *tp); 
 程序例: 
#include <stdio.h> 
 #include <time.h> 
 #include <dos.h> 
int main(void) 
 { 
    time_t t; 
    struct tm *area; 
   t = time(NULL); 
    area = localtime(&t); 
    printf("Number of seconds since 1/1/1970 is: %ld\n", t); 
    printf("Local time is: %s", asctime(area)); 
   t++; 
    area = localtime(&t); 
    printf("Add a second:  %s", asctime(area)); 
   t += 60; 
    area = localtime(&t); 
    printf("Add a minute:  %s", asctime(area)); 
   t += 3600; 
    area = localtime(&t); 
    printf("Add an hour:   %s", asctime(area)); 
   t += 86400L; 
    area = localtime(&t); 
    printf("Add a day:     %s", asctime(area)); 
   t += 2592000L; 
    area = localtime(&t); 
    printf("Add a month:   %s", asctime(area)); 
   t += 31536000L; 
    area = localtime(&t); 
    printf("Add a year:    %s", asctime(area)); 
    return 0; 
 }