Could be...I did not take notes when I started the lighting(DARNIT!!) think I've kept them above 13 hours tho.Aart think about your lighting regimen. One of our friends in Pennsylvania provides 14 hours of light yet her older hens generally molt. Her longest day is about 15 hours. That one hour drop in daylight seems to be enough to trigger a molt.
Am really up in the air about lighting and its effects in a BYC situ...wish I could do a more controlled study.
I'm usually good at detailed data collection, except when I'm not<rolleyes>