how can store datetime value in my database ?

private int  SaveToDB (string st ,string  brt,string  brot, string  spt)
{
    con1.Open();
    SqlCommand cmd = new SqlCommand("dattime", con1);
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Connection = con1 ;
    cmd.Parameters.Add("@st", SqlDbType.DateTime ).Value = label2_time1.Text   ;
    cmd.Parameters.Add("@brt", SqlDbType.DateTime ).Value = label2_brkintime.Text  ;
    cmd.Parameters.Add("@brot", SqlDbType.DateTime ).Value = label3_brkofftm.Text ;
    cmd.Parameters.Add("@spt", SqlDbType.DateTime ).Value = label2_time2.Text ;
    cmd.ExecuteReader();

    con1.Open();
     int  tm = cmd.ExecuteNonQuery();
     con1.Close();
     return tm;

}