from DataGridView saving to text file issue when saving date values on vb.net

I have a problem. Whenever I save data into a text file from a DataGridView, the format of the date gets automatically converted to date along with time. It shouldn't be like that because the data from where the datagridview is basing from is only pure date but when I transfer it into a text file it automatically adds a time. It looks something like this:

246,4/20/2013 12:00:00 AM,01:00:00,p

How do I remove the time (12:00:00 AM) that comes along with the date?

These are codes for the datagrid:

Private Sub load_table()

    sConnection = New MySqlConnection
    sConnection.ConnectionString = "server=localhost;userid=root;password=;database=cph;Convert Zero Datetime=True"

    Dim SDA As New MySqlDataAdapter
    Dim sqlCommand As New MySqlCommand
    Dim bSource As New BindingSource


    Try
        sConnection.Open()
        Dim Query As String
        Query = "select * from swipe_table"
        sqlCommand = New MySqlCommand(Query, sConnection)

        SDA.SelectCommand = sqlCommand
        SDA.Fill(dbDataSet)
        bSource.DataSource = dbDataSet
        DataGridView1.DataSource = bSource
        SDA.Update(dbDataSet)

        sConnection.Close()

    Catch ex As MySqlException
        MessageBox.Show(ex.Message)
    Finally
        sConnection.Dispose()
    End Try
End Sub



Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click


    sConnection = New MySqlConnection
    sConnection.ConnectionString = "server=localhost;userid=root;password=;database=cph;Convert Zero Datetime=True"

    Dim SDA As New MySqlDataAdapter
    Dim sqlCommand As New MySqlCommand
    Dim bSource As New BindingSource
    Try
        sConnection.Open()
        Dim Query As String
        Query = "select * from swipe_table"
        sqlCommand = New MySqlCommand(Query, sConnection)

        SDA.SelectCommand = sqlCommand
        SDA.Fill(dbDataSet)
        bSource.DataSource = dbDataSet
        DataGridView1.DataSource = bSource
        SDA.Update(dbDataSet)

        sConnection.Close()

    Catch ex As MySqlException
        MessageBox.Show(ex.Message)
    Finally
        sConnection.Dispose()
    End Try
End Sub

And these codes are for the saving to text file part:

Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
    Dim filename As String = String.Empty
    Dim sfd1 As New SaveFileDialog()

    sfd1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
    sfd1.FilterIndex = 2
    sfd1.RestoreDirectory = True
    sfd1.Title = "Save Text File"

    If sfd1.ShowDialog() = DialogResult.OK Then
        If sfd1.FileName = String.Empty Then
            MsgBox("Please input filename")
        Else
            filename = sfd1.FileName.ToString
            Saveto_TextFile(DataGridView1, filename)
        End If
    End If
End Sub

Sub Saveto_TextFile(ByVal dvList As DataGridView, ByVal filename As String)
    Dim strDestinationFile As String = "" & filename & ".txt"
    Dim tw As TextWriter = New StreamWriter(strDestinationFile)
    Dim LineToWrite As String = String.Empty

    Try
        For _Row As Integer = 0 To DataGridView1.Rows.Count - 1
            LineToWrite = String.Empty
            For _Column As Integer = 0 To DataGridView1.Columns.Count - 1
                If DataGridView1.Rows(_Row).Cells(_Column).Value IsNot Nothing Then

                    LineToWrite &= "," & DataGridView1.Rows(_Row).Cells(_Column).Value.ToString
                Else
                    LineToWrite &= ","
                End If
            Next
            LineToWrite = LineToWrite.Remove(0, 1) 'remove the first comma
            tw.WriteLine(LineToWrite)
        Next
        tw.Flush()
        tw.Close()
        MessageBox.Show("Data Saved Successfully")
    Catch ex As Exception
        MessageBox.Show("An error occurred")
    End Try
End Sub