When are they no longer ducklings?

[Apyl]

My Pekin is now almost 6 weeks old and the two older Mallards are almost 5 weeks old. All 3 are almost completely feathered, so it feels weird still calling them ducklings. So when exactly are they no longer ducklings?

Here's some pics just because

 

[Lute]

When they lay eggs?

 

[Mum]

They become "fledglings" around 60 days

 

[Oregon Blues]

When their juvenile plumage comes in, I call them juveniles.

I only call them ducklings while they are fluffy.