Incubating Day Count, No such thing as a silly question right?

Discussion in 'Incubating & Hatching Eggs' started by Bens-Hens, Mar 1, 2013.

  1. Bens-Hens

    Bens-Hens Chillin' With My Peeps

    Hi fellow hatchers.

    I have what seems like a fairly simple question regards timing/counting days for our hatch.

    The wife and I are new to this, and what an experience it has been.

    long story short, how does the 21 day cycle start? Day 1 or Day 0?

    We set at 1700 (5pm) on Sunday Feb 10th 13, we thought we were at Day 18 and locked down the incubator PM Wednesday 27th Feb 13, raised humidity and so on. Then, while laying in bed pondering all things hatch (sad, I know) I got to counting the day and wondered if we started the count right, all of a sudden, it was possible that we were actually on Day 17, then I over thought the process and ended up more confused.

    Is the 'set day' Day 0, then 24 hours later Day 1? Or is the 'set day' Day 1, then 24 hours later day 2 starts?

    Trying to find this answer before posting this thread I found a heap of people have hatch days either side of 21, and began to wonder if I am not the only person who began their count incorrectly.

    Thanks for your help in advance,

    Ben and Family.
  2. gina4animals

    gina4animals Chillin' With My Peeps

    Sep 7, 2008
    Salida, CO
    Like all things in nature, it is not exact science Ben. I just mark the calendar on the date I start the incubating process, then estimate 21 days till hatch. Sometimes they hatch on day 21, sometimes day 22 or day 23. I have a brooder hen now that started sitting on eggs about a week ago - so I mark that on the calendar as well and sort of keep track of when her chicks hatch. Don't fret over the exact timing. It will all work out.
  3. stefan333

    stefan333 Chillin' With My Peeps

    Nov 5, 2012
    This is exactly how my brain works. I have spent so much time pondering this question, searching the internet for the answer, trying to figure it up on paper. Glad I'm not the only one who's been wondering this. What I decided to do, in order to not drive myself crazy, is to set the eggs at 6am -that's day one. By the time I get to day 21, it starts at 6am, and I got all day to hover over the incubator waiting for a pip.
  4. Bens-Hens

    Bens-Hens Chillin' With My Peeps

    Hahahaha Thanks for your help.

    I felt silly asking, but had trouble finding the 'actual way' Too much thinking had me worried, too early or on time. Rationally, I think of nature and how a hen would manage and it seems less involved.

    Just scary reading about how first timers make simple mistakes that effect results. This weekend we should know anyway.

    We set 12, lost 4 from infertile at the second candle, then locked down 7, with one that looked less developed than the others, so that one is on the watch list in front of the window.

    I am normally a patient person, but this 21 day business has me stressed and excited all the the same time!
  5. ChickenCanoe

    ChickenCanoe True BYC Addict

    Nov 23, 2010
    St. Louis, MO
    If you don't know something and ask, that isn't silly.
    I did the same when I started.

    I think if the temp is perfect, the eggs are fresh and not too big or too small it should be close.
    Small egs, low humidity and high temp cause early hatch.
    Large eggs, low temp, stale eggs, high humidity and weak chicks(from old breeders, inbreeding, poor nutrition) cause late hatch.

    I think the 3 day high humidity lockdown thing is in case they hatch early.
    My homemade incubator and hatcher can return to temp and humidity fairly fast and my basement usually has high humidity so I usually don't freak out about opening it.
    Last edited: Mar 1, 2013
  6. Bens-Hens

    Bens-Hens Chillin' With My Peeps

    Well, still confused lol

    Some hatched on our Day 20 count the rest on my Day 21. How ever, is we started at zero then it would have been 18-19.

    Any which way, 6 or the 7 that went into lock down made it. Candled the last one and it still have transparent parts and no movement. It had not developed at all further than what it looked like at the Day 18 candle.

    Thank you for your help.
  7. Bens-Hens

    Bens-Hens Chillin' With My Peeps

    During my evening scan I came across another members explaination.

    Cover it pretty well.

    Glad I am not the only one that asked the same question.

    Originally Posted by Brookhavens [​IMG]

    I had the same problem with counting days until an old timer explained it to me. This is what they said:

    Whatever day of the week you set your eggs on is the same day you can expect them to start hatching. (Sometimes earlier. Sometimes later.) You set eggs at 8:00pm on Saturday, March 9th so your hatch day (Day 21) is Saturday, March 30th. Another way to look at it is in hours. Saturday, 3/9 at 8pm is 0 hours. 3/10 at 8am is 12 hours and 8pm on 3/10 is 24 hours. 24 hours = 1 day or Day 1 of incubation. When you read or hear "lock down or stop turning" on Day 18 it means after the full 24 hours of Day 18 has gone by you stop turning. So that would mean that Day 18 ends on Wednesday evening 3/27 @ 7:59pm. Day 19 starts @ 8:00pm Wednesday and lockdown begins. Day 20 starts @ 8pm on Thursday and Day 21 starts @ 8pm on Friday and ends on Saturday @ 7:59pm. So on Saturday at 7:59pm you have had 21 days (each consisting of 24 hours) of full development.

    Thought I would include it here in case someone else does a search.

    Cheers Ben
  8. Ridgerunner

    Ridgerunner True BYC Addict

    Feb 2, 2009
    Northwest Arkansas
    Brookhaven’s description covers it. An egg does not have 24 hours’ worth of development 2 seconds or 2 hours after it is put in the incubator. It takes 24 hours for it to have a day’s worth of development. But that’s not quite as critical as many people think.

    There are a lot of things that can make an egg hatch early or late. Heredity, humidity, how and how long it was stored, or just basic differences in eggs. Smaller eggs tend to hatch earlier than larger eggs. Eggs laid early in a hen’s laying cycle tend to hatch later than eggs laid closer to the molt.

    A really big one is average incubating temperature. If your average incubating temperature is a little high, they can hatch early. I’ve had some pipping when I went into lockdown. My incubator was running a little warm. If the average temperature is low, they can be quite late.

    A couple of times I’ve had eggs hatch 2 full days early under a broody, let alone how I mess up an incubator. Others have posted they have had eggs under a broody be very late. Most of the time, the hatch is over for me within 24 hours of the first one coming out. I’ve had some go on for more than two full days.

    It’s not an exact science. No matter how perfect the conditions, they are not all going to hatch at exactly the same time.
  9. Bens-Hens

    Bens-Hens Chillin' With My Peeps

    Thanks greatly for the reply Ridgerunner.
  10. stefan333

    stefan333 Chillin' With My Peeps

    Nov 5, 2012
    That's a great explanation. I made it even easier on myself. I just bought a new incubator -a Brinsea Mini Advance. It counts the days for me. [​IMG]

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