How to cook boiled eggs:

 There are many methods, each cook has its own, but not everyone knows that the eggs can not be actively boiled. This affects that the egg white becomes rubbery and a smelly gray rind is formed around egg yolk. Eggs should be cooked in gently simmering water, over low heat. Some even pour boiling water in a pot with eggs, cover with a lid and steep them. For hard-boiled eggs water should be changed several times.
 

Cooking time is indicated for large eggs, the average weight of 50-60 grams.

Martha Stewart' Method, so much beloved by many people:

Place the eggs from the refrigerator in a saucepan, cover with cold water and bring to a boil. Then remove from heat, cover with a lid and steep.
For soft-boiled eggs steep for - 90 seconds - 2 minutes.
For hard-boiled eggs steep for - 10-12 min.
After this time, transfer eggs in ice water, or cool them down under cold running water, to stop the cooking process.

My Husband’s Method, which I use,  that has never failed:

Bring water to a boil in a saucepan, put the eggs (from fridge) in a boiling water. Bring to a boil and reduce heat to low and cook, the water should be gently simmering:
For soft-boiled eggs for 6 min after boiling moment
For hard-boiled eggs 12 minutes after boiling moment

After this time, once the eggs should be dipped in ice water, or cool them down under cold running water, to stop the cooking process.

Bon Appétit!