Problems that arise during boiling of eggs is that white of egg comes out of shell and second is formation of green layer between egg white and egg yolk. There are different suggestions for boiling time. Every person will give you different opinion on you boil hard boiled eggs. You can search for this question on internet. They will give you time of boiling according to their results. Best answer is you can choose your time of boiling eggs. You should choose those eggs for hard boiling which are 4 to 5 days old. You can check date of laying for knowing days of eggs. These eggs should be more than three days old. Fresh eggs should not be used for hard boiling because peeling is very difficult in fresh eggs. The membrane above egg white is not mature enough and so breaks while peeling hard shell. 

Another thing while going for hard boiling of egg is that you should bring their temperature to room conditions. This is important if you have stored in refrigerators. This process will save time and energy both.  While boiling eggs right size of pots are very important for boiling. IT is important that you keep your eggs in row not make pile over each other. Pile of eggs will not allow evenly cooking of eggs. So you should avoid hard boiling of eggs in large quantities.

How long do you boil hard boiled eggs is not important as compared to how you cook your eggs. Fill water in the pan but don't overfill it because more water takes longer time to boil. Just keep water level on inch above egg layer. After a full boil of water remove pan from gas and cover it with lid. Keep the pan for about 15 to 17 minutes for eggs to cook well. If you overcook these eggs then this will form green layer above yellow portion of egg. After 20 minutes remove water from pan and cool for 10 more minutes. Your hard boiled eggs are ready to eat. You can peel your eggs or you can also store them for later use.