If I set a hen on a Friday I mark the calendar on a Friday 3 weeks later as 'due date', but start listening for peeping or tapping noises from late Wednesday on.... my silkie mix hen Gracie starts hatching religiously on day 20 no matter what breed egg I give her, often with all chicks out by the morning of day 21. Check on one of the silkie threads to see what their normal is, but I would have any alternative brooder or incubator plans in place by day 19 if you were planning to use them for any 'just in case' scenario.
Many folks have had a problem at hatch time and are scrambling to throw together an emergency brooder, having it planned out ahead of time will save worry later....it also seems that the more you plan for emergencies the less often you need to use the plans!
Many folks have had a problem at hatch time and are scrambling to throw together an emergency brooder, having it planned out ahead of time will save worry later....it also seems that the more you plan for emergencies the less often you need to use the plans!