c# – DateTime to javascript date-ThrowExceptions

Exception or error:

From another answer on Stackoverflow is a conversion from Javascript date to .net DateTime:

long msSinceEpoch = 1260402952906; // Value from Date.getTime() in JavaScript
return new DateTime(1970, 1, 1) + new TimeSpan(msSinceEpoch * 10000);

But how to do the reverse? DateTime to Javascript Date?

How to solve:

Try:

return DateTime.Now.Subtract(new DateTime(1970, 1,1)).TotalMilliseconds

Edit: true UTC is better, but then we need to be consistent

return DateTime.UtcNow
               .Subtract(new DateTime(1970,1,1,0,0,0,DateTimeKind.Utc))
               .TotalMilliseconds;

Although, on second thoughts it does not matter, as long as both dates are in the same time zone.

###

JavaScript Date constructor accepts number of milliseconds since Unix epoch (1 January 1970 00:00:00 UTC). Here’s C# extension method that converts .Net DateTime object to JavaScript date:

public static class DateTimeJavaScript
{
   private static readonly long DatetimeMinTimeTicks =
      (new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).Ticks;

   public static long ToJavaScriptMilliseconds(this DateTime dt)
   {
      return (long)((dt.ToUniversalTime().Ticks - DatetimeMinTimeTicks) / 10000);
   }
}

JavaScript Usage:

var dt = new Date(<%= DateTime.Today.ToJavaScriptMilliseconds() %>);
alert(dt);

###

With Moment.js simply use:

var jsDate = moment(netDateTime).toDate();

Where netDateTime is your DateTime variable serialized, something like "/Date(1456956000000+0200)/".

###

You can try this in your Action:

return DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss");

And this in your Ajax success:

success: function (resultDateString) {
    var date = new Date(resultDateString);
}

Or this in your View: (Javascript plus C#)

var date = new Date('@DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss")');

###

This should do the trick:

date.Subtract(new DateTime(1970, 1,1)).TotalMilliseconds

###

I know this is a little late, but here’s the solution I had to come up with for handling dates when you want to be timezone independent. Essentially it involves converting everything to UTC.

From Javascript to Server:

Send out dates as epoch values with the timezone offset removed.

var d = new Date(2015,0,1) // Jan 1, 2015
// Ajax Request to server ...
$.ajax({
  url: '/target',
  params: { date: d.getTime() - (d.getTimezoneOffset() * 60 * 1000) }
});

The server then recieves 1420070400000 as the date epoch.

On the Server side, convert that epoch value to a datetime object:

DateTime d = new DateTime(1970, 1, 1, 0, 0, 0).AddMilliseconds(epoch);

At this point the date is just the date/time provided by the user as they provided it. Effectively it is UTC.

Going the other way:

When the server pulls data from the database, presumably in UTC, get the difference as an epoch (making sure that both date objects are either local or UTC):

long ms = (long)utcDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;

or

long ms = (long)localDate.Subtract(new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Local)).TotalMilliseconds;

When javascript receives this value, create a new date object. However, this date object is going to be assumed local time, so you need to offset it by the current timezone:

var epochValue = 1420070400000 // value pulled from server.
var utcDateVal = new Date(epochValue);
var actualDate = new Date(utcDateVal.getTime() + (utcDateVal.getTimezoneOffset() * 60 * 1000))

console.log(utcDateVal); // Wed Dec 31 2014 19:00:00 GMT-0500 (Eastern Standard Time)
console.log(actualDate); // Thu Jan 01 2015 00:00:00 GMT-0500 (Eastern Standard Time)

As far as I know, this should work for any time zone where you need to display dates that are timezone independent.

###

This method is working for me:

   public sCdateToJsDate(cSDate: any): Date {
        // cSDate is '2017-01-24T14:14:55.807'
        var datestr = cSDate.toString();
        var dateAr = datestr.split('-');
        var year = parseInt(dateAr[0]);
        var month = parseInt(dateAr[1])-1;
        var day = parseInt(dateAr[2].substring(0, dateAr[2].indexOf("T")));
        var timestring = dateAr[2].substring(dateAr[2].indexOf("T") + 1);
        var timeAr = timestring.split(":");
        var hour = parseInt(timeAr[0]);
        var min = parseInt(timeAr[1]);
        var sek = parseInt(timeAr[2]);
        var date = new Date(year, month, day, hour, min, sek, 0);
        return date;
    }

###

If you use MVC with razor

—–Razor/C#

var dt1 = DateTime.Now.AddDays(14).Date;
    var dt2 = DateTime.Now.AddDays(18).Date;

    var lstDateTime = new List<DateTime>();
    lstDateTime.Add(dt1);
    lstDateTime.Add(dt2);

—Javascript

$(function() {

            var arr = []; //javascript array

            @foreach (var item in lstDateTime)
             {
                @:arr1.push(new Date(@item.Year, @(item.Month - 1), @item.Day));
             }
  • 1: create the list in C# and fill it
  • 2: Create an array in javascript
  • 3: Use razor to iterate the list
  • 4: Use @: to switch back to js and @ to switch to C#
  • 5: The -1 in the month to correct the month number in js.

Good luck

###

<input type="hidden" id="CDate" value="<%=DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss")%>" />

In order to convert the date to JS date(all numbers):

var JSDate = $("#CDate").val();
JSDate = Date.parse(JSDate);

###

Another late answer, but this is missing here. If you want to handle conversion of serialized /Date(1425408717000)/ in javascript, you can simply call:

var cSharpDate = "/Date(1425408717000)/"
var jsDate = new Date(parseInt(cSharpDate.replace(/[^0-9 +]/g, '')));

Source: amirsahib

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