Molting - How long does this take?

[Happy Chooks]

So excited, the molt must be over after 3 long eggless months, 6 eggs yesterday. Not bad for 7 girls.

Yes, it's great when you start getting eggs again.

 

[Namow71]

I keep seeing everyone say theirs molt in fall/winter one of my girls is starting now (I think) and she is not a very nice girl at the moment. She's even intimidating the dogs and pecked at me a few times this morning. I'm going to take all the advice I've read on here.
I have a Buff and a Amer, she's the one in molt and they are about 1 year old. Is normal for a first molt in spring? Thanks.