/*函数原型char*asctime(struct tm* tblock)  tblock为日期和时间的结构体指针*/
#include<stdio.h>
#include<time.h>
#include<stddef.h>
#include<dos.h>
int main(void)
{time_t t;
struct time d_time;
struct data d_data;
struct tm *local;
getdata(&d_data);/*获取日期*/
gettime(&d_time);/*获取时间*/
t=dostounix(&d_data,&d_time);
local=localtime(&t);/*本地化*/
printf("Time and Data :%s\n",asctime(local));/*转换为ASCII码并显示*/
return 0;
}

没引用头文件呗