MonthFromTime.js 1014 Bytes
'use strict';

var DayWithinYear = require('./DayWithinYear');
var InLeapYear = require('./InLeapYear');

// https://262.ecma-international.org/5.1/#sec-15.9.1.4

module.exports = function MonthFromTime(t) {
	var day = DayWithinYear(t);
	if (0 <= day && day < 31) {
		return 0;
	}
	var leap = InLeapYear(t);
	if (31 <= day && day < (59 + leap)) {
		return 1;
	}
	if ((59 + leap) <= day && day < (90 + leap)) {
		return 2;
	}
	if ((90 + leap) <= day && day < (120 + leap)) {
		return 3;
	}
	if ((120 + leap) <= day && day < (151 + leap)) {
		return 4;
	}
	if ((151 + leap) <= day && day < (181 + leap)) {
		return 5;
	}
	if ((181 + leap) <= day && day < (212 + leap)) {
		return 6;
	}
	if ((212 + leap) <= day && day < (243 + leap)) {
		return 7;
	}
	if ((243 + leap) <= day && day < (273 + leap)) {
		return 8;
	}
	if ((273 + leap) <= day && day < (304 + leap)) {
		return 9;
	}
	if ((304 + leap) <= day && day < (334 + leap)) {
		return 10;
	}
	if ((334 + leap) <= day && day < (365 + leap)) {
		return 11;
	}
};