Javascript Date() is changing the date

Question

I'm pulling events from google calendar.

I'm able to see an event date:

var date = when.split("T")[0];
console.log(date);

This outputs 2016-01-07. Then I put it into an array inside an object:

allEvents.push({
    eventDate:date,
    eventTime:time,
    eventTBD:TBD
});

Then, when I go to grab the date again:

$.each(allEvents, function(i, v){
    var eventDate = new Date(v.eventDate);
    if(eventDate > startDate && eventDate < endDate){
        console.log(v.eventDate);
        console.log("Show This Date: " + eventDate);    
    }
});

For January, I get this output:

2016-01-07
Show This Date: Wed Jan 06 2016 19:00:00 GMT-0500 (EST)

for March, I get this output:

2016-03-19
Show This Date: Fri Mar 18 2016 20:00:00 GMT-0400 (EDT)

It's showing the day before the date I just showed... It seems to be 5 hours off? Do I need to account for this? How do I do so?

It seems the `date()` does account for DST, but why is it moving back my times by 5 hours? — ntgCleaner, Jan 05 '16 at 20:09
@DanielA.White I'd like the actual date (made by `date()`) to show up correctly in my timezone and not 5 hours behind — ntgCleaner, Jan 05 '16 at 20:12
You're creating a date object without timezone info. Easiest way out of this is to use the UTC methods on the date object. — Matthew, Jan 05 '16 at 20:13
like this answer? http://stackoverflow.com/questions/20834411/specify-timezone-in-javascript — ntgCleaner, Jan 05 '16 at 20:14
for a simple hack, can I just add 1 to the "day"? This is for my eyes only. — ntgCleaner, Jan 05 '16 at 20:15
@ntgCleaner That's not reliable and will work very poorly in time-zones that are ahead of UTC (they'd be two days ahead instead). If it's for your eyes only and you're always going to access it from the same place, then I don't see why not. — Paul, Jan 05 '16 at 20:19

score 3 · Answer 1 · answered Nov 20 '20 at 04:26

3

I know this is old, but may help somebody.

I solved this issue by adding the time on the Date argument:

var eventDate = new Date(v.eventDate + ' 00:00:00');

You can remove it after

answered Nov 20 '20 at 04:26

lucianov88

185
3
10

Worked perfectly for me. Thanks kind stranger! – KingOfDaNorth Mar 03 '22 at 13:18

score 0 · Answer 2 · answered Jan 05 '16 at 20:31

The default timezone when parsing a date is UTC. If you want to use the client timezone you can adjust the date so that it occurs at the right time in the browser's timezone:

var eventDate = new Date(v.eventDate);
var ms_per_minute = 60000;
eventDate.setTime( eventDate.getTime() + eventDate.getTimezoneOffset()*ms_per_minute );

Otherwise you can just use UTC whenever you display the date:

console.log("Show This Date: " + eventDate.toUTCSTring() );

score 0 · Answer 3 · answered Jan 05 '16 at 20:41

I think moment.js could help you on date manipulation.

Here is a fiddle for u

jQuery(document).ready(function($) {
  var the_date_string = $('#in-date > pre').text();
  var result = moment(the_date_string, 'YYYY-MM-DD'); //here is more info about that http://momentjs.com/docs/#/parsing/string-format/
  $('#out-date > pre').text(result);


});

body {
  font-family: arial;
}

<script src="http://momentjs.com/downloads/moment.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h1 id="in-date"> INPUT: <pre>2016-01-07</pre></h1>
<h1 id="out-date"> OUTPUT: <pre></pre></h1>

Thumbs up if u liked it! :)

[EDIT] If u just want the client timestamp (in internationals formats) you can easly use the moment() function

Javascript Date() is changing the date

3 Answers3

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