inserting time stamp into database

[weijian]

Here'e the code:

Dim objConn As New OleDbConnection(strDSN)
Dim objCmd As New OleDbCommand("nwsInsert", objConn)
objCmd.CommandType = CommandType.StoredProcedure

'get the input time
Dim dttDate As DateTime
dttDate = Date.Now.UtcNow

objParam = New OleDbParameter("@postedon", OleDbType.DBTimeStamp)
objParam.Value = dttDate
objCmd.Parameters.Add(objParam)

'execute the append
objCmd.Connection.Open()
objCmd.ExecuteNonQuery()
objCmd.Connection.Close()
objConn.Dispose()

I'm trying to access an Access database, and the @postedon parameter is supposed to be inserted into a field of type Date/Time and the format is General Date. I tried various OleDbType - DBTimeStamp, DBDate, Date, DBTime, Char - all resulted in "System.Data.OleDb.OleDbException: Data type mismatch in criteria expression." What is the right way to add dates?