Depends on what sort of egg, but basically the development time of an egg will not be affected by outside factors.
It takes 5 hours to hatch.
It takes 12 hours to hatch a T-Rox in My Singing Monsters
27 hours
To hatch from the egg, depending on the type of egg, it will take 31-32 hours to hatch. This is about a day and a half, or to be more specific 1 day 7-8 hours.
24 hours
It takes 14 hours to breed and hatch in DragonVale.
12 hours?!! Press the middle button on the tamagotchi, then set the time, date, your birthday, etc. Then after about 5 minutes it will hatch.
about 30-32 hours
About 48 hours.
24 hours
It can vary depending on the species, but on average (such as for Canadian geese) they takes from 25 to 30 days to hatch, and in a clutch it takes from 8 to 36 hours to hatch (relative to the first egg that hatches). Every gosling will take about 24 more hours to become mobile after they hatch.
It takes two hours, but you have to be online during the time it is incubating. So, you might as well just go off doing whatever you want and when you're online for about two hours check it and it should hatch. God-Birds take twenty-four hours to hatch.