For as long as Easter eggs and spring flowers have marked the first signs of spring, so too has Ben & Jerry’s Free Cone Day. Well, okay, maybe not that long. But the annual ice cream event has been going strong since 1979.. Free Cone Day returns to Ben & Jerry’s on Tuesday, April 9, from 12 p.m. to 8 p.m. for its 40th consecutive year. If you’re not familiar with how the lactose-loving holiday works, you’re in for a tasty treat — or as many treats as you’d like, to be exact! That’s because Ben & Jerry’s will give you a cup or cone of any flavor you like, then you can get right back in line for seconds (or thirds or fourths) — no fake mustache or wig needed. Unlike many giveaways or freebies, there are zero strings attached — no apps to download, no coupons to cut,…