Do you believe in late sitting in the office?Suppose your office hours is 9 am to 5 pm and your boss sits late hours everyday,what should you do?

Technically, once work time is over the boss cant force you to work without paying you overtime. But, if you are not busy and nothing better to do at home its smart to stick around and observe your boss and find out why he stays up too late. if its because he has too much work to do, volunteering to assist to lighten the load goes a long way and extends goodwill. This shows that you have initiative and is actually concerned of your boss.

You were given a time frame to complete your task extending is not really adivisable because it oly shows that your not efficient to complete your task .. 

Well, my boss makes me to come early every day and as well sitting late every day irrespective whether he or we have work or not. Upon that, he make us to come every weekend saturdays. 

Official working hours is 8 to 5 and 2 days weekend off.

But for us 7.30 AM to 7.00 Pm and saturday 9.30 AM till he goes home.. some time 2.00 PM and some time 2.30 PM, whenver he feels hungry... Dam it. 

If your boss asks you to stay to support him, you need to stay in full team working spirit. He may not be asking you to help on daily basis.

Again, in team working spirit, you can offer your boss to help in some presentation or calculation or whatever may be. He may give you something to do and tell you that you may go home. This is much cordial approach

But, if you are not busy and nothing better to do at home its smart to stick around and observe your boss and find out why he stays up too late. if its because he ... I believe everyone should know the time management if we have a certain office hours so we know how to finish our job in that particular time.

yes why not because its my boss order 

I believe everyone should know the time management if we have a certain office hours so we know how to finish our job in that particular time ,,sometimes as per situation we have to do overtime no in that case its ok to work late hours

Time Management is the essence of work place. Late sitting rarely depending on heavy work load is ok , but I am not in favour to make it a routine . There should be a balance in work  & family life. May be boss has some special assignments from Management .