Starbucks in South Korea will close its storefronts for a half-day next week so employees can attend a history lesson as the coffee chain faces widespread criticism over a “Tank Day” promotion.

The campaign advertising Starbucks’s new “Tank” coffee thermos for bigger coffees was launched on the 46-year anniversary of the Gwangju Uprising, a series of pro-democracy protests against former dictator Chun Doo-hwan in which at least 165 people were killed, but other sources put the death toll in the thousands.