## Posted By

wizard04 on 09/02/11

# Get time intervals between two Dates

/ Published in: JavaScript

`/* Get time intervals between two Dates v2.0 *  * This work is licensed under a Creative Commons Attribution 3.0 Unported License * http://creativecommons.org/licenses/by/3.0/ * * Author: Andy Harrison, http://dragonzreef.com/ * Date: 16 September 2011 */ Date.isLeapYear = function(year){ return (year%400 == 0 || (year%4 == 0 && year%100 != 0)); }Date.prototype.isLeapYear = function(){ return Date.isLeapYear(this.getFullYear()); } //get the number of days in a given month of a given year (month being 0-11)Date.daysInMonth = function(year, month){ return ([31, (Date.isLeapYear(year)?29:28), 31,30,31,30,31,31,30,31,30,31])[month]; }Date.prototype.daysInMonth = function(){ return Date.daysInMonth(this.getFullYear(), this.getMonth()); } //returns an object with time intervals between two Dates//Date objects, milliseconds, or date strings are accepted arguments//object properties: years, months, weeks, days, hours, minutes, seconds, milliseconds//each part is *in addition* to the sum of the larger parts; e.g., if there are 17 days between the two dates, .weeks==2 and .days==3Date.timeBetween = function(dateA, dateB){	dateA = new Date(dateA);	dateB = new Date(dateB);	if(isNaN(dateA.valueOf()+dateB.valueOf())) return null;	//invalid date(s) 	if(dateA.valueOf() > dateB.valueOf())	{		var tmp = dateA;		dateA = dateB;		dateB = tmp;	} 	var parts = {}; 	//years	parts.years = dateB.getFullYear() - dateA.getFullYear(); 	//months	dateA.setFullYear(dateB.getFullYear());	parts.months = dateB.getMonth() - dateA.getMonth(); 	//days	dateA.setMonth(dateB.getMonth());	if(dateA.valueOf() > dateB.valueOf())	{		dateA.setMonth(dateA.getMonth()-1);		parts.months--;	}	parts.days = Math.floor((dateB.valueOf()-dateA.valueOf())/86400000); 	//time	parts.hours = dateB.getHours() - dateA.getHours();	parts.minutes = dateB.getMinutes() - dateA.getMinutes();	parts.seconds = dateB.getSeconds() - dateA.getSeconds();	parts.milliseconds = dateB.getMilliseconds() - dateA.getMilliseconds(); 	//weeks	parts.weeks = Math.floor(parts.days/7);	parts.days = parts.days%7; 	//adjust for negative values	if(parts.milliseconds < 0){ parts.milliseconds = 1000+parts.milliseconds; parts.seconds--; }	if(parts.seconds < 0){ parts.seconds = 60+parts.seconds; parts.minutes--; }	if(parts.minutes < 0){ parts.minutes = 60+parts.minutes; parts.hours--; }	if(parts.hours < 0) parts.hours = 24+parts.hours;	if(parts.months < 0){ parts.months = 12+parts.months; parts.years--; } 	return parts;}`