Welcome to BYC! Glad you decided to join our flock. Your question is a bit confusing. Are you asking if you return on the 27th day of December will your eggs be hatched by then? If so, it depends on what date they went (or will go into the incubator). Or are you asking if you return on the 27th day of your eggs being in the incubator, will they be hatched by then? Is so, then the answer is definitely "yes." All the eggs that are going to hatch will have hatched before the 27th day as chicken eggs typically take 21 days to hatch. Maybe you can clarify your question for us. Please feel free to ask any questions you may have. We are here to help in any way we can. Good luck with your hatch.