There are chickens near enough to the equator that they never see 14 hours of daylight, yet they lay as well as any other chickens of those breeds. Don’t get too hung up on 14 hours as a magic number.
Light is important to chickens. When days get shorter, they molt and quit laying. When days get longer, they lay. I know. First year pullets will often skip the molt and lay through their first winter but after that they molt when the days get shorter.
The 14 hour old wives tale does have a basis. When commercial operations can control all the light their chickens see, they use that as part of their cycle. They keep the light short until the pullets are old enough to lay commercial sized eggs. Then they change the feed and lengthen the light to kick-start them into laying. Part of that process is putting out just enough feed that the hens can clean it up at one time, then not feeding them until they are hungry again. This keeps the food hogs from stuffing themselves and keeping the non-dominant ones from being kept away from the food. That way all the hens get the right amount of food to lay a grade A large egg. The 14 hours is what they have settled on with their feeding cycles to get the right amount of food into the hens.
Many people think that by keeping 14 hours of light, their hens will never molt. That depends on where you live. If you live far enough away from the equator that your chickens see more than 14 hours of light, they may start a molt when the days get shorter before they get down to 14 hours.
Many people believe there is something magic about 14 hours. Not really. The days getting longer or shorter has a lot more effect than the actual length of the days.
As far as your location, as long as you can see to read a newspaper there, they are getting enough light. It’s a good question but I think you are worrying about something you shouldn’t.