C program to print the calender of given month and year or to print the day for given input of year,month and day

Here I am providing you with two programs,first program takes the date as an input and prints day as the output and the second program prints the entire month's calender as output.Both this program were made by me in first year of my engineering and now uploading it in little modified form with explanation and hope you all find this useful.Both the program works for the date range of 1901-2099.