This is probably too late for the original commenter, but the way to figure out approximately when an AP starts it to get the publishing date for the first book and add 2,700 years AR. So since Ruins of Azlant was published in August 2017, it's probably set in 4717 AR. I usually go a step further and translate the start month similarly, but I'm not sure that's necessary.
Reading the details on the adventure background can confirm this. On page 24 "Captain Ancorato discovered the island in early 4715 AR", and on page 6 "Three years ago, that nation dispatched dozens of ships to survey islands approximately 300 miles south of the old Sun Temple Colony to determine their suitability for building a new colony." That would put the survey expedition starting in 4714 AR and succeeding in early 4715 AR, which makes sense.