Belarus not intolerant of religious diversity
Over 80% of the religious population of Belarus belongs to the Byelorussian and Russian Orthodox Churches. Around 10-12% of believers are Roman Catholic and Uniate. Protestants make up about 1-2%. The remainder represent non-Christian religions.
Given the above, Belarus would have been within its rights to grant only eastern Orthodox Christmas (January 7) the status of an official holiday. However, both dates are recognised by a government the United States claims is intolerant and discriminatory in religion.