A program in C to find out the day on a particular date.

year.c

/*
 * Filename : year.c
 * Author : Aryan Garg, B. Tech 1st Year, GLAU
 * Modifier : Divyansh Bhardwaj, Technical Trainer, GLAU
 * Aim : To find the day of the week on a given date.
 * */
#include<stdio.h>
int main()
{
    int year = 0, date = 0, month = 0, last_two_digits = 0, temp_m = 0, temp_l = 0,
    temp_o = 0, century_code = 0, temp_p = 0, week_code = 0;

    printf("Enter the date: ");
    scanf("%d", &date);

    printf("Enter the month (1 for Jan, 2 for Feb and so on...): ");
    scanf("%d", &month);

    printf("Enter the year: ");
    scanf("%d", &year);


    last_two_digits = year % 100; //Extracing last two digit of year
    temp_m = last_two_digits + date; //add date in last two digit number of year

    switch (month)
    {
        case 1  :
        case 10 :   temp_l = temp_m + 1;
                    break;
        case 2  :
        case 3  :
        case 11 :   temp_l = temp_m + 4;
                    break;
        case 4  :
        case 7  :   temp_l = temp_m + 0;
                    break;
        case 5  :   temp_l = temp_m + 2;
                    break;
        case 6  :   temp_l = temp_m + 5;
                    break;
        case 8  :   temp_l = temp_m + 3;
                    break;
        case 9  :
        case 12 :   temp_l = temp_m + 16;
                    break;

        default:    printf("Error 1");  //  error 1 means switch case failed,
                                        // value of month is invalid or zero
    }

    if (last_two_digits % 4 == 0)     //code for checking leap year
    {
        if (month == 1 || month == 2)  //if date is in january or
                                       // february one is to be subtracted
        {
            temp_o = temp_l - 1;
        }
        else
        {
            temp_o = temp_l - 0;
        }

    }
    if ( year >= 1700 && year < 1800 )       // add century code
    {
        century_code = temp_o + 4;
    }
    else if ( year >= 1800 && year < 1900 )
    {
        century_code = temp_o + 2;
    }
    else if ( year >= 1900 && year < 2000 )
    {
        century_code = temp_o + 0;
    }
    else if( year >= 1900 && year < 3000 )
    {
        century_code = temp_o + 6;
    }
    temp_p = century_code + last_two_digits;           //add last digit of year with century_code
    week_code = temp_p % 7;  //week code will come
    switch (week_code)
    {
        case 0  :   printf("Sunday");
            break;
        case 1  :   printf("Monday");
            break;
        case 2  :   printf("Tuesday");
            break;
        case 3  :   printf("Wednesday");
            break;
        case 4  :   printf("Thursday");
            break;
        case 5  :   printf("Friday");
            break;
        case 6  :   printf("Saturday");
            break;
        case 7  :   printf("Sunday");
            break;
        default: printf("Error 2"); // Error 2 means the final switch failed
                                    // value of week_code is invalid or zero
    }
    return 0;

}

The program seems to be off, it prints Wednesday on 4 12 2018