Starbucks Korea said it will close all of its stores nationwide at 3 p.m. on June 22 to conduct mandatory training for employees on historical awareness and social sensitivity.

The company said store staff will receive the training through video sessions at each location after the early closures.

The measure follows criticism over a May 18 marketing promotion for stainless-steel tumblers labeled “SS Tank”, which the company presented as “Tank Day.” The promotion was launched on the anniversary of the May 18 Gwangju Uprising in South Korea, a date of major historical significance in the country.