From experience and what I have read, you should leave the Grow lights on 15 to 16 hours a day. That usually works fine for any type of seedlings. Look at this article and it'll confirm it.
How Long Should I Leave My Vegetable Seed Starts Under ...
What do you know about plants and grow lights ?
Good question. :). It sent me searching. I found a variation ranging from 12-15 hours of light a day. They also recommend raising the light as the plants grow to maintain a 4-6" distance.
This site was helpful.
https://www.gardeners.com/how-to/how-to-start-seeds/5062.html