They do not celebrate Easter (or Christmas) as religious holidays.

Worker Quote: In the year 325 Constantine called the Nicene Council which added to the holy days the day of Easter. They accepted this now into Christianity with its bunny rabbits and eggs because it was a celebration of fertility. And that’s the way things got added into Christianity. (Leo Stancliff, History of the church)

Worker Sermon about Easter Sunday by John Porterfield