Hi Sudarshan,
Actually this should have been a separate thread as it is not linked to the original question.
Anyway, You need max(timestamp) logic which can be conveniently written in SQL script based Calc view. Please refer to the thread below on similar line. Lars has provided a SQL statement which uses MIN (date column) which you can modify with MAX.
http://scn.sap.com/thread/3319917
Regards,
Ravi