The Farmers I deal with have no dates on their chickens, 'sell by' or 'use by'.
If the chicken you purchased was frozen on the date in question and not subsequently thawed and refrozen, it should be perfectly fine. When Farmers have excess, they freeze what they can't sell fresh.
I don't know what the attraction is these day's of anything called a 'Farmers Market'.
I frequent some road side markets in Wisconsin and even there you find things for sale that were purchased commercially for sale just as if you were in a Supermarket.
I ALWAYS inquire whether the item for sale was raised by the seller and the pedigree. Getting to know the seller is a requirement to sourcing true non-commercially raised meat and produce. There are commercial small producers i purchase from such as Pinn Oaks for lamb but before purchasing I do my research.-Dick