https://news.dunkindonuts.com/news/summer-free-ze-celebrate-the-first-day-of-summer-with-complimentary-sample-of-dunkin-donuts-frozen-lemonade
Thursday, June 21 guests at participating Dunkin’ Donuts nationwide are invited to enjoy a complimentary sample (3.5-ounce) from 10 AM to 2 PM, while supplies last