Postal holiday
Part 608, section 3.2 of the DMM (U.S. Domestic Mail Manual) groups holidays into "Widely Observed" and "Not Widely Observed". Holidays "Widely Observed" include New Year’s Day, Memorial Day, Independence Day, Labor Day, Thanksgiving Day, and Christmas Day. Holidays "Not Widely Observed" are Martin Luther King, Jr.’s Birthday; Presidents Day; Columbus Day; and Veterans Day.
Postal holiday-3