Laying season for all pheasants ,no matter where you live in North America, is from mid to late March until the end of July or first part of August at the latest. 16 week old birds will certainly not breed. They may horse around and act stupid but your birds will not actively be productive until next spring. Hope this helps a little and good luck with your birds.
You can actually make them lay eggs with lights and if you are getting around 14 hours of daylight then your birds will still produce eggs and will breed. For example 1 week ago here in California we were still getting fertile eggs from out pheasants because we were still getting a lot of light. We were not reaching maximum egg production but still getting some eggs. Which were fertile. But if you raise your pheasants next to something and they are getting a lot of artificial light plus daylight then they will produce eggs and breed.