According to the Gregorian calendar, it was Monday on the date 01/01/1900. If any year is input through the keyboard write a program to find out what is the day on 1st January of this year.

CH-2 [C] (d).c

#include <stdio.h>

int main()
{
    int curentYear, baseYear, leapYear, no_leapYear, totalNo_ofDay, year, di;
    printf("enter current year=");
    scanf("%d", &curentYear);
    baseYear = 1900;
    year = (curentYear - 1) - baseYear;
    leapYear = (year / 4);  //because 1900 is not leap year
                                           //for leap year see CH-2[F] (a).c
    no_leapYear = year - leapYear;
    totalNo_ofDay = (365 * no_leapYear) + (366 * leapYear) + 1; // +1 bec. day ofjan 1 of currentYear
    di = (totalNo_ofDay % 7);
    if (di == 0)
        printf("day is monday");
    else if (di == 1)
        printf("day is tuesday");
    else if (di == 2)
        printf("day is wdnessday");
    else if (di == 3)
        printf("day is trusday");
    else if (di == 4)
        printf("day is friday");
    else if (di == 5)
        printf("day is saturday");
    else if (di == 6)
        printf("day is sunday");
    else
        printf("some thing went wrong");
return 0;
}