What's the longest your eggs have taken to hatch?

[jimbowk]

I incubated 9 eggs, 5 hatched on day 21, how long should I let the other 4 stay in the incubator?,

 

[budimwe]

I've just gone into Lockdown with my first hatch (chicken eggs).. and was curious to see how long to leave them...
I know 21 days - May 5th is the 21st day...
But how many days later should I wait to call it over??

My first hatch ever was due on April 24. All the eggs that I gathered were laid on the same day. My first two chicks (which looked like Barred Rocks) hatched on day 21. Three more chicks (possibly Leghorns) hatched on day 22. On day 23, two more chicks hatched (I think Welsummers), and this morning on day 25, another reddish orange chick hatched. There are three more viable eggs in the incubator, so I'm waiting until day 28 before I toss them.

 

[Heartsopenwide]

Always nice when something unexpected happens. . . Most of my hatches last well into day 23, though. My Marans always take forever, and any chick I ever have hatch must follow a rule. That rule is - If someone else is zipping or hatching, or just hatched 10 minutes ago. . . Wait. Don't hatch. Don't even zip.

What is the longest? I have BCM eggs that didn't hatch yet. Day 25