c 根据日期获得星期

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

int main(void)
{
    struct tm *mytime;
    time_t cur;
    char buf[50];
    time(&cur);

    mytime = localtime(&cur);
    strftime(buf, 50, "%Y-%B-%d %A", mytime);
    puts(buf);
    mytime->tm_year = 110;
    mytime->tm_mon = 1;
    mytime->tm_mday = 4;

    cur = mktime(mytime);
    mytime = localtime(&cur);

    //printf("Year: %d\nMonth of Year: %d\nDay of Month: %d\nDay in Week: %d\n", mytime->tm_year+1900, mytime->tm_mon, mytime->tm_mday, mytime->tm_wday);

    strftime(buf, 50, "%Y-%B-%d %A", mytime);
    puts(buf);

    return 0;
}