You must note that the OLTAS System through which Bank Receives all Direct Tax Payment and records PAN wise or TAN wise works up to 8.00 P.M. So never logon to Bank Site for payment of Tax after 8.00 P.M. This may land up yourself in to finding out lost money in the Bank Channel for 2/3 days which can lead to sleepless night.
Particulary on 30th. September, the last date of filing I.T.Returns for 2008-09 assessment year, pay all self assessment tax before 8.00 P.M.