Write a program in C to calculate the day on 1st Jan of any year

#include<stdio.h>

#include<math.h>
int main()
{
	int  ld,fd,yr;
	long int nd,td;
	
	printf("Enter year");
	scanf("%d",&yr);
	nd=(yr-1)*365L;
	ld=(yr-1)/4-(yr-1)/100+(yr-1)/400;
	td=nd+ld;
	fd=td%7;
	
	if(fd==0)
	printf("n Monday");
	
	if(fd==1)
	printf("n tuesday");
	
	if(fd==2)
	printf("n Wednesday");
	
	if(fd==3)
	printf(" n Thrusday");
	
	if(fd==4)
	printf(" n Friday");
	
	if(fd==5)
	printf(" n Saturday");
	if(fd==6)
	printf(" n Sunday");
	
	return 0;
	
	
	
}