Update google map after 40 seconds so that my google map updated in ASP.Net

Please refer below code.I have set refresh of google map every 10 seconds,you can set it to 45 secons(45000 ms).

HTML

<div>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>
    <script type="text/javascript">
        window.onload = function () {
            LoadGoogleMap();
            setInterval(function () {
                LoadGoogleMap();
            }, 10000);
        }
        function LoadGoogleMap() {
            var markers = GetMapData();
            var mapOptions = {
                center: new google.maps.LatLng(markers[0].Latitude, markers[0].Longitude),
                zoom: 8,
                mapTypeId: google.maps.MapTypeId.ROADMAP
            };
            var infoWindow = new google.maps.InfoWindow();
            var map = new google.maps.Map(document.getElementById("dvMap"), mapOptions);
            for (i = 0; i < markers.length; i++) {
                var data = markers[i]
                var myLatlng = new google.maps.LatLng(data.Latitude, data.Longitude);
                var marker = new google.maps.Marker({
                    position: myLatlng,
                    map: map,
                    title: data.Name
                });
                (function (marker, data) {
                    google.maps.event.addListener(marker, "click", function (e) {
                        infoWindow.setContent(data.Description);
                        infoWindow.open(map, marker);
                    });
                })(marker, data);
            }
        }

        function GetMapData() {
            var json = '';
            $.ajax({
                type: "POST",
                url: "CS.aspx/GetData",
                data: "{}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                async: false,
                success: function (resp) {
                    json = resp.d;
                },
                error: function () { debugger; }
            });
            return json;
        }
    </script>
    <div id="dvMap" style="width: 500px; height: 500px">
    </div>
</div>

C#

[WebMethod]
public static List<object> GetData()
{
    List<object> lists = new List<object>();
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    SqlCommand cmd = new SqlCommand("select * from Locations");
    using (SqlConnection con = new SqlConnection(conString))
    {
        cmd.Connection = con;
        cmd.Connection.Open();
        using (SqlDataReader sdr = cmd.ExecuteReader())
        {
            while (sdr.Read())
            {
                lists.Add(new
                {
                    Name = sdr["Name"],
                    Latitude = sdr["Latitude"],
                    Longitude = sdr["Longitude"]
                    Description = sdr["Description"]
                });
            }
        }
        cmd.Connection.Close();
    }
    return lists;
}

Screenshot