Problem with Javascript Date function in IE 7, returns NaN

Question

I have a twitter feed and I create a new date obj so I can format the date to my liking.

var created = new Date(this.created_at) works in firefox and c

Answer 1

Here is what I made to correct this!

$tweetList.append('<p><span class="twitterdate">' + parseTwitterDate(item.created_at) + location + '</span></p>');

var month=new Array();
month[0]="January";
month[1]="February";
month[2]="March";
month[3]="April";
month[4]="May";
month[5]="June";
month[6]="July";
month[7]="August";
month[8]="September";
month[9]="October";
month[10]="November";
month[11]="December";

function parseTwitterDate($stamp) {
    var v=$stamp.split(' ');
    var date = new Date(Date.parse(v[1]+" "+v[2]+", "+v[5]+" "+v[3]+" UTC"));
    var hour = date.getHours();
    var ampm = hour<12 ? ' AM' : ' PM';
    return date.getHours() +':'+ date.getMinutes() +' '+ ampm +' '+ date.getDate() +' '+ month[date.getMonth()] +' '+ date.getFullYear();
}

And this give me "19:38 PM 23 April 2012" on Chrome, IE and Firefox.

Answer 2

You'll want to make sure the date is parsed as UTC, because otherwise javascript will interpret it as a date in your local timezone.

The date looks like this: Tue Jul 13 23:18:36 +0000 2010

You can parse it like this:

function parseDate(str) {
  var v=str.split(' ');
  return new Date(Date.parse(v[1]+" "+v[2]+", "+v[5]+" "+v[3]+" UTC"));
} 

Which will give the correct date/time in the local timezone, for example: Tue Jul 13 2010 19:18:36 GMT-0400 (EDT)

So that should leave your code looking something like this:

$(function(){
  $.getJSON("http://twitter.com/statuses/user_timeline/google.json?count=1&callback=?", function(data){
    $.each(data, function(){
      var created = parseDate(this.created_at);
      $("<div></div>").append("<ul><li>Unformatted: " + this.created_at + "</li><li>Formatted: " + created + "</li></ul>").appendTo("body");
    });
  });
  function parseDate(str) {
    var v=str.split(' ');
    return new Date(Date.parse(v[1]+" "+v[2]+", "+v[5]+" "+v[3]+" UTC"));
  } 
});

Answer 3

I've found the jQuery Globalization Plugin date parsing to work best. Other methods had cross-browser issues and stuff like date.js had not been updated in quite a while.

You also don't need a datePicker on the page. You can just call something similar to the example given in the docs:

$.parseDate('yy-mm-dd', '2007-01-26');