That's for soft boiling, surely? Hard-boiled eggs are usually left in for longer. What I do for mine: put in cold water, place on medium heat until water begins to boil (~9 mins), deactivate hob and leave for 12 mins, rinse with cold water, dry and place in fridge, leave for 12-18 hours at least. When ready to eat: peel off shell, remove skin that's left near the air pocket, stuff in piehole.
(They're fine to eat immediately after boiling, of course, with the warmth making them actually quite tasty - but it's risky. Until they've done their time in the fridge, they're often difficult to peel and/or they'll have a lot of hard-to-remove skin left on them once peeled.)