The Martin Luther King Jr. holiday on Jan. 20, 2020, marks the 25th anniversary of the day of service that celebrates the Civil Rights leader’s life and legacy. Observed each year on the third Monday in January as “a day on, not a day off,” MLK Day is the only federal holiday designated as a national day of service to encourage all Americans to volunteer to improve their communities. The Corporation for National and Community service has been charged to lead this effort for the last quarter century.