Rahul,
All of it depends upon solution implemented as per business needs, plus the training which you need to give to the users which has to be part of your scope before go-live. This will make sure that most of the hiccups are already handled in UAT. Of course after go-live you have stabilizing process but that again depends upon scenarios, volume of data etc. and understanding of the user. So can't judge on the basis of certain areas as they are also linked to complete solution plus master data etc..
I would suggest you to have complete understanding of the solution you are implementing along with scenario's which you need to cover while testing (from the inputs of end-users and blue-print document/as-is document) and decide on the basis of the same the timeline.
Regards
Rahul