timestamp datatype is to avoid locking for updates
timestamp is an Adaptive Server supplied user-defined datatype that is defined as varbinary(8) NULL. Because timestamp is a user defined datatype, you can not use it to define other datatypes. timestamp datatype does not hold date or time value and cannot be convert into date or time . timestamp holds binary-type data .
We can use tsequal function to check for timestamp value to prevent update on a row that has been modified since it was selected for browsing.
Ooops, I apologize, Raj is correct. There indeed *does* exist the 'special' type of timestamp (I was looking in my ASE Quick Ref guide which doesn't mention it). It sounds like you wish to know the date and time a row was last modified.
If so, place an update trigger on the row which updates a datetime or smalldatetime with getdate()