Here's a thought, Harriet, and 
welcome to BYC!!
Molting hens should be treated as tho' they are convalescing - plenty of rest and once they start turning that corner towards better health - plenty of good food. 
As they become more healthy and active, that seems like the time to allow them longer days.
My 2 year old hens always molted in October. The light is failing fast at that time (well, it 
fails fast right up until December 21st around here 
). My idea has been to allow things to run on an outdoor schedule until about November 1st. By then, the weather really begins to deteriorate and darkness rather than light is in control outdoors.
The birds often have late Autumn days when they don't want to be out in the wind, rain and snow and would rather stand around in the coop and 
gossip, anyway 
.
If you live where the weather and sunlight allows for molting at this time of year, that's probably far more of a natural environment than up here near 49° North. They need at least a month of rest . . . may as well be December 
.
Just my thoughts . . .
Steve