Raw javascript date to VB.net datetime

I have a javascript AJAX call passing a javascript date object to an ASP.Net MVC controller. Here is the AJAX call:

  var timestamp = new Date();
  $.ajax({
    url: '',
    type: 'POST',
    data: { username: username,
            timestamp: timestamp,
            hash: ''},
    dataType: 'json',

(I have omitted some sensitive values, but the important bits are there).

The controller has an object for the parameters being passed which gets populated just fine.

Public Class AjaxParams
   Public Property Username As String
   Public Property Hash As String
   Public Property Timestamp As String
End Class

And here is the controller declaration:

<HttpPost()> _
Public Function RetrieveSalt(params As AjaxParams)

When making a call to the controller, all of the parameters get correctly passed and populate the AjaxParams object.

However, later on in my code, I am trying to convert the passed javascript date from its string representation into a VB.net DateTime object. I created a function to do this which works ok for some dates but it simply is not robust enough to convert all necessary date formats and is failing on a number of dates.

Here is one of the failing date formats that must be converted:

Tue Sep 17 2013 07:01:36 GMT+0600 (ALMT)

Here is the function I created:

Public Function TryParseDate(dDate As String) As Date

    Dim enUK As New CultureInfo("en-GB")
    Dim Converted_Date As Nullable(Of Date) = Nothing
    Dim Temp_Date As Date
    Dim formats() As String = {"ddd MMM d yyyy HH:mm:ss 'GMT'zzzz '(BST)'", _
                               "ddd MMM d yyyy HH:mm:ss 'GMT'zzzz '(GMT)'", _
                               "ddd MMM d yyyy HH:mm:ss 'GMT'zzzz", _
                               "ddd MMM d yyyy HH:mm:ss 'UTC'zzzz"}

    ' Ensure no leading or trailing spaces exist
    dDate = dDate.Trim(" ")

    Select Case True
        Case IsNumeric(dDate)
            Dim Unix_Date As Long = Long.Parse(dDate)

            Try
                Dim newDate As Date = New DateTime(1970, 1, 1, 0, 0, 0, 0)
                Converted_Date = newDate.AddMilliseconds(Unix_Date)
            Catch ex As Exception
                Converted_Date = Nothing
            End Try

        Case Else

            Try
                Converted_Date = JsonConvert.SerializeObject(dDate)
            Catch ex As Exception

                ' Find the location of the first opening bracket
                Dim OpeningBracket As Integer = dDate.IndexOf("(")
                Dim DateLength As Integer = dDate.Length

                ' Remove the trailing timezone abbreviation in brackets
                dDate = dDate.Remove(OpeningBracket, DateLength - OpeningBracket)

                ' Ensure no leading or trailing spaces exist
                dDate = dDate.Trim(" ")

                ' Attempt standard conversion and if successful, return the date
                If Date.TryParse(dDate, Temp_Date) Then
                    Converted_Date = Temp_Date
                Else
                    Converted_Date = Nothing
                End If

                ' Standard date parsing function has failed, try some other formats
                If IsNothing(Converted_Date) Then
                    If Date.TryParseExact(dDate, formats, enUK, DateTimeStyles.None, Temp_Date) Then
                        Converted_Date = Temp_Date
                    Else
                        Converted_Date = Nothing
                    End If
                End If
            End Try
    End Select

    Return Converted_Date

End Function

Either I am missing something really simple here or parsing the date format into a DateTime object with timezone info, etc is a real pain.

Does anyone have any ideas on how best to accomplish this??