I thought about doing that (forget about dates, pay attention to how they look). I have some turkey eggs from this set that look a little behind, and the next set goes into lockdown the day this hatch is scheduled, so stragglers will just be left in the tray for a few more days.
Oops! I fear that happening here...I had all my sets, mixed chickens and turkeys, stragglers up to 3 days after a set, 4 trays running...and nothing but a few scribbles on an envelope to decode my egg marks.
Yesterday I went through and made my "daily watch" list. It's pretty full. :-) And...