So this is day 4.5: Exciting stuff. That dark little blob with veiny bits is a baby duck! 3 of the 6 eggs looks like duds (not unexpected since I got them so late after the USPS delivery mess). 2 are definitely growing, and 1 is a solid maybe.
Day one starts the morning after I set them (put in the incubator) since I set them at night. Yaaaaay! They aren’t all dead!