Interesting. It’s after the Fall Equinox and you’re still getting more than 12 hours of daylight. I’m sure not, about 11-1/2 hours for me. And practically all my hens are still laying. Only one is molting and she was broody and raising chicks. They often molt early when doing that.
It’s not a cut and dried simple answer. Do all chickens need 12 hours of daylight to lay eggs? No, not at all. Some breeds, like Australorps, are well known for laying well in winter when days are short. Some chickens do shut down or at least slow down in winter. Even chickens of the same breed don’t all behave the same.
It’s normal for chickens to molt when the days get shorter and quit laying. Some start laying again when they finish the molt and some wait until spring to crank back up. Not all chickens are the same.
To further complicate it, yours are pullets that have just started to lay. It’s fairly normal for some pullets to skip the molt their first winter and continue laying whether you extend the light or not. Not all pullets do that and breed can have an influence, but many do keep laying.
I’ve had experience all over the board with this. I do not extend the light. I’ve had pullets start laying the first week of December, the shortest days of the year. I often have pullets that lay through their first winter, but I’ve had some shut down too. I’ve had hens that start laying some really nice eggs when they finish the molt, even if it is the middle of winter. I’ve had some wait until spring after their molt.
I can’t tell you what will happen with yours. They may keep laying until next fall 2015 whether you extend the lights or not. Some or all may shut down for the winter and crank back up in the spring. Extending the lights does increase the chances they will continue to lay but even that is not a guarantee.