時間處理：計算下一天日期,如輸入"2004/12/31"(註釋2014年12月31日)，則輸出"2005/1/1".

/*
 ============================================================================
 Name         : Exercise.c
 Author       : haier
 Version      : 0.01
 Copyright   : Your copyright notice
 Description : Ansi-style, Compile by Code:Blocks, Platform Linux
 ============================================================================
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define SECONDS_PER_DAY (60*60*24)

typedef struct date
{
    unsigned year;
    unsigned month;
    unsigned day;
} Date;

void nextDay(char *test)
{
    struct tm time,*tm_ptr;
    time_t seconds;
    Date myDate;
    char *p;

    /*轉換時間字符串*/
    p = strtok(test, "/");
    myDate.year=atoi(p);
    p = strtok(NULL, "/");
    myDate.month=atoi(p);
    p = strtok(NULL, "/");
    myDate.day=atoi(p);

    /*填充struct tm*/
    time.tm_year = myDate.year - 1900;
    time.tm_mon  = myDate.month - 1;
    time.tm_mday = myDate.day;
    time.tm_hour = 12; //默認爲該日12:00:00
    time.tm_min  = 0;
    time.tm_sec  = 0;
    seconds=mktime(&time)+SECONDS_PER_DAY;  //轉換tm結構爲time_t類型值，並加一天

    /*轉換並打印日期*/
    tm_ptr = gmtime(&seconds);
    printf("%d/%d/%d\n",tm_ptr->tm_year+1900, tm_ptr->tm_mon+1, tm_ptr->tm_mday);
}

int main()
{
    char strTime[20];

    printf("Please input the date : ");
    scanf("%s",strTime);

    nextDay(strTime);

    return 0;
}

運行示例：