I have two Cocktail they laid three eggs and it’s been 21 days and the egg has not hatched yet. It has hope and possible to hatched around other days.
Cockatiel eggs will generally hatch between 18-21 days – but this is from the day they start sitting on the eggs, not from the day the egg is laid. Since eggs are laid every other day, the last egg will hatch several days after the first, again depending on when incubation began. I generally recommend waiting 7 days after the last egg is due to hatch before you discard them. Generally the parents will stop sitting on them by that time if the eggs are not any good.
Thank you for asking Lafeber,