i set mine on the 5th hoping for a day early chick, i started with 3 dozen fertile trader joe eggs, as i cant find any other fertile eggs around where i live at this time, so i candled all before they went in took out 6 that had cracks, so the 30 went in, candled on saturday and it seems maybe around 8 or 9 are developing, which is pleanty for me, but this is actually my second chance for december babys, as i had another batch going but i lost electricity and they all died got down to like 55 degrees or so in middle of the night for like 9 hours, so i started over with 3 new dozens, but i will do another candling this saturday to make sure of developing ones and the non developing ones, and get a final count, but i am hoping for a christmas born chick, so wish me luck