Bantam hatching when to put on lockdown

[Party_Chicken]

I've got a dozen frizzled Cochin hatching eggs in my incubator, three are duds so I've got 9 fertile eggs. I've seen some thing that say you need to put them on lock down on day 16 which I've just remembered is today. The lady I bought the eggs from told me hers have always hatched closer to day 21 but she wouldn't be surprised if my incubator being more consistent would hatch them on day 19. What should I do?

 

[MysteryChicken]

Well, day 16 is fine for both Bantam, & LF chicken eggs.
My bantam eggs usually hatch day 21, very rarely have I had any hatch at day 19 - 20.

I've had LF eggs hatch between day 19 - 25.

These are from both incubator, & broody hen hatches.

 

[Party_Chicken]

Well, day 16 is fine for both Bantam, & LF chicken eggs.
My bantam eggs usually hatch day 21, very rarely have I had any hatch at day 19 - 20.

I've had LF eggs hatch between day 19 - 25.

These are from both incubator, & broody hen hatches.

Oh ok. Thanks for the help!