Executive Order 5625—Saturday Working Hours, Field Service, Department of the Interior
It is hereby ordered that four hours, exclusive of time for luncheon, shall constitute a day's work on Saturdays for all clerks and other employees of the field service of the Department of the Interior; and all Executive or other orders in conflict herewith are hereby revoked.
It is provided, however, that this order shall not apply to any bureau or office, or to any of the clerks or other employees thereof, that may for special public reasons be excepted therefrom by the head of said department, or where the same would be inconsistent with the provisions of existing law.
The White House,
May 18, 1931.
Herbert Hoover, Executive Order 5625—Saturday Working Hours, Field Service, Department of the Interior Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/361230