Well, my last batch of bantams hatched out on the 18th day, without any issues with being "premies". Now, I have seramas, a few silkie mixes and some OEGB in the hatcher, on day 19, and one just hatched out. I thought that I had read about bantams maybe hatching closer to day 19 instead of 21, but then someone else said that they should all hatch on the 21st day. My incubator is not off, it's a 1588, and I checked my thermometer with several different thermometers. I was actually expecting these guys to hatch on the 10th, put them in the hatcher last night or the night before. Today, there was no excitement, except the usual temp/humidity check. Then, I went in to fill the water for the coturnix quail, and heard banging around in the hatcher, and one was hatching (had it's head in the shell still) and another was banging around. So... umm, when are banties SUPPOSED to hatch?