Syntax error converting datetime from character string

Getting this error when updating a row via a gridview with a sqldatasource in Vb.net/SQL Server 2000. No matter what input (1/1/2010, blank, etc) I give it I can't seem to get it right.

Code before the input is passed to the sp:

    Dim sqldatenull As DateTime
    Dim DateVerify As DateTime
        sqldatenull = DateTime.MaxValue
    If (e.NewValues("Date_Start") Is Nothing) Then
        e.NewValues("Date_Start") = sqldatenull
    Else
        DateTime.TryParse(e.NewValues("Date_Start").ToString, DateVerify)
        MsgBox("Worked!")
        e.NewValues("Date_Start") = DateVerify
    End If

SP:

@ISTag varchar(10),
@PCISTag varchar(10),
@User varchar(50),
@Date_Start datetime,
@Date_End datetime,
@Status varchar(50),
@Cost money,
@Notes varchar(500),
@CreatedBy varchar(50),
@ModifiedBy varchar(50)
AS
BEGIN
    SET NOCOUNT ON;

    EXEC sp_changeLog 'HardDrive', @ISTag, @ModifiedBy

    UPDATE T_HardDrive
        SET PCIStag = @PCISTag,
            [User] = @User,
            Date_Start = @Date_Start,
            Date_End = @Date_End,
            [Status] = @Status,
            Cost = @Cost,
            Notes = @Notes,
        ModifiedBy = @ModifiedBy
        WHERE ISTag = @ISTag

SQLDatasource definition:

<asp:SqlDataSource ID="InventoryHardDrive" runat="server" 
                        ConnectionString="<%$ ConnectionStrings:InventoryConnectionString %>" 
                        DeleteCommand="DELETE FROM [T_HardDrive] WHERE [ISTag] = @original_ISTag" 
                        InsertCommand="sp_HardDriveInsert" InsertCommandType="StoredProcedure" 
                        OldValuesParameterFormatString="original_{0}" 
                        SelectCommand="sp_HardDriveSelect" SelectCommandType="StoredProcedure" 
                        UpdateCommand="sp_HardDriveUpdate" UpdateCommandType="StoredProcedure">
                        <DeleteParameters>

                        </DeleteParameters>
                        <InsertParameters>
                            <asp:Parameter Name="ISTag" Type="String" />
                            <asp:Parameter Name="PCISTag" Type="String" />
                            <asp:Parameter Name="User" Type="String" />
                            <asp:Parameter Name="Date_Start" Type="DateTime" />
                            <asp:Parameter Name="Date_End" Type="DateTime" />
                            <asp:Parameter Name="Status" Type="String" />
                            <asp:Parameter Name="Cost" Type="Decimal" />
                            <asp:Parameter Name="Notes" Type="String" />
                            <asp:Parameter Name="CreatedBy" Type="String" />
                            <asp:Parameter Name="ModifiedBy" Type="String" />
                        </InsertParameters>
                        <SelectParameters>
                            <asp:ControlParameter ControlID="hideInactiveCheckBox" Name="Active" 
                                PropertyName="Checked" Type="Boolean" />
                            <asp:ControlParameter ControlID="filterText" DefaultValue="%" Name="ISTag" 
                                PropertyName="Text" Type="String" />
                        </SelectParameters>
                        <UpdateParameters>
                            <asp:Parameter Name="ISTag" Type="String" />
                            <asp:Parameter Name="PCISTag" Type="String" />
                            <asp:Parameter Name="User" Type="String" />
                            <asp:Parameter Name="Date_Start" Type="DateTime" />
                            <asp:Parameter Name="Date_End" Type="DateTime" />
                            <asp:Parameter Name="Status" Type="String" />
                            <asp:Parameter Name="Cost" Type="Decimal" />
                            <asp:Parameter Name="Notes" Type="String" />
                            <asp:Parameter Name="CreatedBy" Type="String" />
                            <asp:Parameter Name="ModifiedBy" Type="String" />
                        </UpdateParameters>
                    </asp:SqlDataSource>

If I leave the box empty the value is set to "12/31/9999 11:59:59 PM". Is this not the correct format for DateTime?

Error:

Syntax error converting datetime from character string. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.Data.SqlClient.SqlException: Syntax error converting datetime from character string.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace: 


[SqlException (0x80131904): Syntax error converting datetime from character string.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1951450
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4849003
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
   System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2394
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +204
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162
   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +175
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +137
   System.Web.UI.WebC开发者_如何学JAVAontrols.SqlDataSourceView.ExecuteDbCommand(DbCommand command, DataSourceOperation operation) +386
   System.Web.UI.WebControls.SqlDataSourceView.ExecuteUpdate(IDictionary keys, IDictionary values, IDictionary oldValues) +325
   System.Web.UI.DataSourceView.Update(IDictionary keys, IDictionary values, IDictionary oldValues, DataSourceViewOperationCallback callback) +92
   System.Web.UI.WebControls.GridView.HandleUpdate(GridViewRow row, Int32 rowIndex, Boolean causesValidation) +907
   System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +704
   System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) +95
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
   System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) +123
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
   System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +118
   System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +135
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +175
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565

My guess would be that you're trying to store a date in SQL Server that exceeds the range of its date type. .NET's DateTime will happily store dates some millenia into the future, but SQL Server is more limited.

Why don't you use a nullable DateTime instead, and pass actual null (or better yet, DBNull) when you have to?