HI, welcome to the forum. Glad you joined.
I don't know how long those outages lasted or how cool the eggs actually got, but some of my broody hens leave their eggs for over an hour each day, occasionally twice a day. Brinsea markets an incubator where you can program in letting the eggs cool some each day, they say it helps. The studies they linked was mostly geese, not chickens, but the principle should still be the same. There are many stories on here where eggs were left to cool for several hours and the eggs were still fine. I had a broody hen do that once, she was off most of the day one day and still hatched 11 of 11 eggs. It is not something that you want to happen but it's usually not catastrophic.
Did you count the days right? That's a real common mistake on here. An egg does not have a day's worth of incubation when it goes into the incubator. It tales 24 hours before you should say "1" when you start counting. An easy way to check your counting is that the day of the week you set them is the day or the week the 21 days are up. If they went in the incubator on a Monday, the 21 days is up on a Monday.
Not all eggs hatch at 21 days anyway. For many different reasons an egg might hatch two days early or late. That could be due to heredity, humidity, how and how long the eggs were stored before incubation started, or just differences in the eggs. If the average incubator temperature is warmer they can be early, cool and they can be late. Many different reasons they can be early or late.
No, not yet. Some of my hatches, broody hen or incubator, are over less than 24 hours after the first one hatches. I like those. I've had some drag out more than 48 hours. These are nerve wracking. One incubator hatch I had one hatch late in the day. It took about 24 hours for another to external pip, that was just before I went to bed. Not hatch, just pip. When I woke up the next morning there were 16 new chicks in there. Patience can be your friend.
I hesitate to mention this because some people reading it think it can be helpful or fun to do earlier in incubation. I consider it a last minute desperation move just before you toss the eggs, not something to do for fun. It's a float test. Only do this if the egg has not pipped. No holes in the egg.
If you place an egg in a bowl of water that has incubated for three weeks, it should float because it has lost so much moisture. If a live chick is in the egg that late in incubation the egg should wiggle in the water so put it back in the incubator. If it does not wiggle this late in incubation there is not a live chick in there. That might make you feel better abut tossing the eggs. I'd probably wait another two days before I tried this.
Good luck and once again,
