Javascript serialization of DateTime in asp.net is not giving a javascript date object?

Question

When I parse a DateTime to json in .Net it returns a string (i.e. "\/Date(1249335194272)\/"). How do I make it return a js Date object constructor not wrap in a string?

// js server code
var dteNow = <%= jsonDateNow %>;


// js rendered code
var dteNow = "\/Date(1249335477787)\/";


// C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.Script.Serialization;
using System.Web.UI.WebControls;

namespace testing{
    public partial class iTaxPrep : System.Web.UI.Page
    {
        protected string jsonDateNow;
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                jsonDateNow = new JavaScriptSerializer().Serialize(DateTime.Now);

            }
        }
    }
}

Solution 1

This seems to work (Thanks Chris S for the idea). In the C# do a replace to remove the string wrapper from around the date object;

    using System.Collections.Generic;
        using System.Linq;
        using System.Web;
        using System.Web.UI;
        using System.Web.Script.Serialization;
        using System.Web.Script.Services;
        using System.Web.Services;
        using System.Web.UI.WebControls;

        namespace test
        {
            [ScriptService]
            public partial class testing: System.Web.UI.Page
            {
                protected string strCaseID;
                protected string jsonCase;

                protected void Page_Load(object sender, EventArgs e)
                {
                    if (!IsPostBack)
                    {
                        strCaseID =Tools.GetQueryObject("id");
                        // get a complex object with dates, string, arrays etc.
                        jsonESHACase = new JavaScriptSerializer().Serialize(objCase.Get(strCaseID ))
                            .Replace("\"\\/Date(", "new Date(").Replace(")\\/\"", ")");
                    }
                }
            }
        }

..and after removing the quotes and adding the new prefix to Date this js now works. Hooray!

testCase= <%= jsonESHACase %>;
    if (testCase) {
        document.write(testCase["ClosingDate"].format("MM dd yyyy"));
    }

Solution 2

This is a known limitation with JSON. This answer might help you, specifically:

value = new Date(parseInt(value.replace("/Date(", "").replace(")/",""), 10));

Solution 3

Simple javascript manipulation like this:

function(param){
  var date = new Date(parseInt(param.substr(6)));
  return date;
}

Pass in JSON date as param to the function and it will return a javascript date.

Solution 4

With a little string manipulation and an eval you can create a Date object

var dteNow = "\/Date(1249335477787)\/";
var dteObj = eval("new " + dteNow.replace(/\//g,""));

Solution 5

Slightly simpler string clean up with RegEx:

var myDate = "\\/Date(1508821200000)\/";    
var jsDate = new Date(parseInt(myDate.replace(/\D/g, '')));

View more solutions

Comments

[Jenn Briden]

The actually problem is that I need to serialize objects to JSON that contain dates and use those dates client-side.

[Jenn Briden]

That is pretty much what I ended up doing but when I parse a large object containing several dates and other info this will start looking ugly.

[Carl Sharman]

I much prefer this answer to the other answers that fix the problem in JS. The problem is in .Net, so should be resolved in .Net IMO.

[Flexo]

A lot of your answers seem to contain very little content beyond just a link to your blog post. Any chance you can expand upon them to make them into real answers? The rest look great and I'm sure the blog posts will make great answers as well.

[ruffin]

eval is evil etc etc, but otherwise nicely done.

[dhruvpatel]

This works fine for me: value = new Date(parseInt(value.replace("/Date(", "").replace(")/",""))); I guess the 10 in the second arguments not necessary as it appends time 10:00 in the date. Dates I am working on are coming from server and they have the time configured in it, so I don't want that to be changed. Thanks for your answer though!

[inki]

The 10 in the second argument is necessary, it is the radix argument for parseInt. It does not append anything. It specifies the type the radix or base, and without it may behave differently on different systems.

[MordechayS]

@webdeveloper the parseInt argument is in Javascript The Good Parts (definitely worth a read) - it's one of the many hidden features of Javascript. It assumes you are base 8 basically

[Dave Cousineau]

what is this even doing? DateTime dt1 = dt does nothing.