The third egg was laid overnight on the 7th/8th but egg four wasn't laid until the 10th. And it is not usual for hatchings to space out over a couple/three days, just happens in this case that 1-3 hatched quickly - interestingly enough 34 days after incubation began which I believe was the same as last year. So, if "baking time" is the same for all (big supposition), today would be early, tomorrow would be 34 days. That kind of delay is not a problem. A week between hatches, is more problematic, but given how much food Ivy has traditionally brought into the nest for the chicks, food wouldn't be much of a problem either, he doesn't seem to have problems keeping up with his kids' increasing appetites.