Javascript datetime issue

Question

I have a code which stores the startdate toUTCString and endate toUTCString in a table. When I debug the code in console javascript is showing some strange behaviour.

The output in console

 var startdate = new Date($("#smdatestart").val()).toUTCString();
 var enddate = new Date($("#smdateend").val()).toUTCString();
 var now = new Date();
 var currUTCDate = now.toUTCString();//current datetime
startdate //starting date
"Mon, 02 Dec 2013 07:30:00 GMT" //in UTC
currUTCDate // current date
"Mon, 02 Dec 2013 07:15:16 GMT"  //in UTC
enddate // ending date
"Sun, 01 Dec 2013 18:30:00 GMT" //in UTC


currUTCDate > enddate //should be true but showing false
false
startdate > enddate //should be true but showing false
false
startdate > currUTCDate // this output is correct
true

$("#smdatestart").val() = "12/2/2013 1:00:00 PM" $("#smdateend").val() = "12/2/2013 12:00:00 AM" — Furquan Khan, Dec 02 '13 at 07:36
Well, those strings are not in a format which makes them comparable. They start with the weekday, i.e. the order of the strings is determined by the order of the weekdays. A comparable format wouldn't contain weekdays at all, and would like something like `YYYY-MM-DD HH:MM:SS`. [Compare the time value of the date objects](http://stackoverflow.com/q/7606798/218196), not the string. — Felix Kling, Dec 02 '13 at 07:37
possible duplicate of [JavaScript Date Object Comparison](http://stackoverflow.com/q/7606798/218196) — Felix Kling, Dec 02 '13 at 07:41
The values in `startdate`, `enddate`, `currUTCDate` are String, not Date object. You are actually comparing the String representation of the Date's alphabetically, not comparing the actual Date's. — Arie Xiao, Dec 02 '13 at 07:44

score 1 · Answer 1 · answered Dec 02 '13 at 07:43

var startdate = new Date('Mon, 02 Dec 2013 07:30:00 GMT');
var enddate = new Date('Sun, 01 Dec 2013 18:30:00 GMT');
var currUTCDate = new Date('Mon, 02 Dec 2013 07:15:16 GMT');

startdate > enddate // true

currUTCDate > enddate // true

Anything involving '=' should use the '+' prefix. It will then compare the dates millisecond values.

+startdate  <= +currUTCDate ;  => true
+startdate >= +currUTCDate ;  => true
+startdate === +currUTCDate ; => true

Milind Anantwar · Accepted Answer · 2013-12-02T07:46:11.960

0

I would recommend you for first comparing dates in date format. And if condition satisfies, convert the data to utcstring and store them according to your need.

edited Dec 02 '13 at 07:46

answered Dec 02 '13 at 07:35

Milind Anantwar

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Indranil.Bharambe · Answer 3 · 2013-12-02T07:47:09.063

0

When using == or != or > or < if the types of the two expressions are different it will attempt to convert them to string, number, or Boolean etc
use below code to compare

if ( Date.parse ( currentdate) > Date.parse ( enddate) ) {
    // your code
}

edited Dec 02 '13 at 07:47

answered Dec 02 '13 at 07:39

Indranil.Bharambe

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Javascript datetime issue

3 Answers3