April 19 The first Boston Marathon was held on this date way back in 1897. This year’s race has been delayed until Oct. 11 and limited to 20,000 runners, in the hopes that COVID restrictions will have eased by then. April 20 It’s 4/20—the unofficial national marijuana holiday. Its origins date back to 1971, when a group of California teens regularly met at 4:20 p.m to smoke weed, according to History.com. But the holiday of late has entered the mainstream, and countless brands will again seize on it this year. Ad Age Next: Retail, a virtual conference focused on what’s ahead for the ...