How Long to Bake 15 Boneless Chicken Breasts?

I’m making a pesto chicken - basically boneless chicken breasts marinated in pesto but I’m baking 15 breasts at one time and I’m perplexed by how long they should bake. I’ve googled extensively and read 25 minutes to over an hour.

Any experts that can help with larger quantities? I’m planning on using a meat thermometer but need to have some sense of time so I can plan for my dinner party. Thanks for any help!!

thank you so much!!:smiley: