How do I use AJAX to get a ServerSide computation for getting Server Date

Your pretty far off course there. Read the lesson below to get a better idea of how to do it.

I don't care for the examples too much, but it's all I could find in a short amount of time. I attached a sample I wrote in VB, but you should get the idea.

And you'll have to learn json if you select this style or method of talking to the server in the background. Don't forget to jaon lint everything during testing.
http://jsonlint.com/[^]

Simply put, you need a jquery file that calls the webservice, which is a asmx file, or webservice, that is tweaked to support json.

Introduction to using jQuery with Web Services[^]

http://www.c-sharpcorner.com/UploadFile/dacca2/understand-jquery-ajax-function-call-web-service-using-jque/[^]

So an example post script would be like this, which includes error checking and so forth, and url encoding and decoding of test during transmitting and receiving.

There are several ways to do this, but this is what I use. Some folks like json stringify to encode and decode json.

function apply_post() {

    var secure_Token,
    m_template;

    m_secureToken = $('[id*="_txt_Secure_Token_Field"]').val();
    m_jobName = $('[id*="_txt_CE_FI_SaveAs_Field"]').val().replace(/[|&$%@"<>()+,] /g, '');
    
    // Package the data for transmission
    var send_Data =
    "{" +
    "\"p_secureToken\" : \"" + m_secureToken + "\", " +
    "\"p_jobName\" : \"" + escape(m_jobName) + "\"  " +
    "}";

    $('[id*="_updateProgress_Unified"]').fadeIn('fast');

    $.ajax({
        type: "POST",
        contentType: "application/json; charset=utf-8",
        url: "broadcastEditor.asmx/apply_Post",
        data: send_Data,
        dataType: "json",
        error: function (xhr, status, error) {
            var exitCode = 2;
            $('[id*="_updateProgress_Unified"]').fadeOut('fast', function () {
                alert(xhr.responseText);
            });
        },
        success: function (responseText) {
            var objB = jQuery.parseJSON(responseText.d);
            var exitCode = objB.exitCode;
            var p_jobNumber = unescape(objB.p_jobNumber.replace(/\+/g, ' '));
            var p_jobStatus = unescape(objB.p_jobStatus.replace(/\+/g, ' '));

            if (0 === exitCode) {
                $('[id*="_lbl_CE_SM"]').text(m_jobName + ' has been posted successfully');
                $('[id*="_div_CE_SM_Container"]').css('background-color', 'rgb(28,134,238)');
            }
            else {
                $('[id*="_lbl_CE_SM"]').text(p_saveAs + ' has failed to be posted');
                $('[id*="_div_CE_SM_Container"]').css('background-color', 'rgb(176,23,31)');
            }
            $('[id*="_lbl_CE_Status_JobNumber_Field"]').text(p_jobNumber);
            $('[id*="_lbl_CE_Status_JobsStatus_Field"]').text(p_jobStatus);
            $('[id*="_div_CE_SM_Container"]').fadeIn('normal').delay(5000).fadeOut('normal');
            $('[id*="_updateProgress_Unified"]').fadeOut('fast');

        }
    });

}

And a asmx file

Imports System.Web.Services
Imports System.Text
Imports System.Web
Imports System.IO
Imports System.Xml.Serialization
Imports System.Data.SqlClient

<webservice(namespace:> _
<webservicebinding(conformsto:> _
<global.microsoft.visualbasic.compilerservices.designergenerated()> _
<system.web.script.services.scriptservice()> _
Public Class ws_broadcastEditor_SQL
    Inherits System.Web.Services.WebService
    <webmethod(enablesession:> _
<webmethod(enablesession:> _
    Public Function apply_Post( _
        ByVal p_secureToken As String,
        ByVal p_jobName As String) As String

        Dim dwExitCode As Integer = 2
        Dim json_response As StringBuilder = New StringBuilder

        Dim m_jobName As String = HttpUtility.UrlDecode(p_jobName)
        Dim m_jobNumber As String = Nothing
        Dim m_jobStatus As String = Nothing

        'Toggle the Publish Flag tp On or 1
        dwExitCode = publish_Job(
            m_jobName,
            m_jobNumber,
            m_jobStatus
        )

        'Just tell the user whether the file data write was sucessful or not
        With json_response
            .Append("{")
            .Append(" ""exitCode"" : " & dwExitCode.ToString & ", ")
            .Append(" ""p_jobNumber"" : """ & HttpUtility.UrlEncode(m_jobNumber) & """, ")
            .Append(" ""p_jobStatus"" : """ & HttpUtility.UrlEncode(m_jobStatus) & """  ")
            .Append("}")
        End With

        Dim js As System.Web.Script.Serialization.JavaScriptSerializer = New System.Web.Script.Serialization.JavaScriptSerializer
        js.Serialize(json_response.ToString)
        js = Nothing

        Return json_response.ToString

    End Function