program to get the day on 1st january of the input year.

 //This code is designed by codenation.

// 22:24 Mon 16/11/2020

//Consider there was Monday on 01/01/1900

#include<stdio.h>

int main()
{
    
    
    
    int yr, lp_yrs,normal_years, difference, total_days, day_of_week;
    
    printf("Enter the year above 1900:");
    scanf ("%d", &yr);
    
    difference = yr-1900;
    
    lp_yrs = difference / 4;
    
    normal_years=difference-lp_yrs;
    
    total_days = (normal_years*365) + lp_yrs*366 ;
    
    day_of_week = total_days % 7;
    
    switch(day_of_week)
    {
        case 0:
            printf("The day on Jan 1st of this year is Monday");
            break;
        case 1:
            printf("The day on Jan 1st of this year is Tuesday");
            break;
        case 2:
            printf("The day on Jan 1st of this year is wednesday");
            break;
        case 3:
            printf("The day on Jan 1st of this year is Thursday");
            break;
        case 4:
            printf("The day on Jan 1st of this year is friday");
            break;
        case 5:
            printf("The day on Jan 1st of this year is saturday");
            break;
        case 6:
            printf("The day on Jan 1st of this year is sunday");
            break;
        
    }
    
}