C + + implements an example of a method to determine the day of the week by year month and day based on zekim larsen calculation formula

In this paper, the method of determining the day of the week by the year, month and day based on the calculation formula of C + + is illustrated. I will share it with you for your reference as follows:

#include <iostream>
#include <string>
using namespace std;
int whatday(int y, int m, int d) {
  //  Return to the correct week. with  0 - 6  said   week  1 - 7
  if(m==1||m==2)
  {
    y--;
    m+=12;
  }
  return(d+2*m+3*(m+1)/5+y+y/4-y/100+y/400)%7;
}
string weekday[7] = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};
int main() {
  int y, m, d;
  cin >> y >> m >> d;
  cout << weekday[whatday(y, m, d)] << endl;
  return 0;
}

PS: here are some other time and date related tools for your reference:

Online date/days calculator:
http://tools.ofstack.com/jisuanqi/date_jisuanqi

Online date calculator/day difference calculator:
http://tools.ofstack.com/jisuanqi/datecalc

Online date days difference calculator:
http://tools.ofstack.com/jisuanqi/onlinedatejsq

Unix timestamp (timestamp) conversion tool:
http://tools.ofstack.com/code/unixtime

I hope this article has helped you with C++ programming.