Question

Well I know this question is asked a thousand times on internet but I am a rookie and don’t know much about Javascript functions. I want to compare two date.
Input is in form = “2011-jan-21”

Here is what I have come up, Please help! I will really appreciate because I need to get it worked urgently.

   function compareDates() {
            var startDate=document.getElementById("startDate").value;
            var endDate = document.getElementById("endDate").value;
                months = {'jan': '01', 'feb': '02', 'mar': '03', 'apr': '04', 'may': '05',
                'jun': '06', 'jul': '07', 'aug': '08', 'sep': '09', 'oct': '10', 'nov': '11',
                'dec': '12'};
                split = startDate.split('-');
                var newStartDate = [split[2], months[split[1]], split[0]].join(',');

                split = endDate.split('-');
                var newEndDate = [split[2], months[split[1]], split[0]].join(',');

                var myDate=new Date();
                myDate.setFullYear(startDate);
                console.log(newStartDate);

                var myDateEnd=new Date();
                myDateEnd.setFullYear(endDate);

             if (myDate < myDateEnd) {
                alert ("Error !");
             }
        }


<form method="POST" id="myForm" onsubmit="compareDates()">
        <input id="startDate" />
        <input id="endDate" />
        <input type="Submit" />

    </form>

Answer 1

Just pass the string to a Date constructor. Much easier.

var startDate = new Date(document.getElementById("startDate").value);
var endDate = new Date(document.getElementById("endDate").value);

Now you’ve got two full-fledged Date instances that you can work with as you please.

function compare()
{
    var startDate = new Date(document.getElementById("startDate").value);
    var endDate = new Date(document.getElementById("endDate").value);

    if (startDate.getTime() > endDate.getTime())
    {
        alert ("Error !");
    }
}