DayFromYear.js 323 Bytes
'use strict';

var GetIntrinsic = require('../GetIntrinsic');

var $floor = GetIntrinsic('%Math.floor%');

// https://ecma-international.org/ecma-262/5.1/#sec-15.9.1.3

module.exports = function DayFromYear(y) {
	return (365 * (y - 1970)) + $floor((y - 1969) / 4) - $floor((y - 1901) / 100) + $floor((y - 1601) / 400);
};