Okla. Stat. tit. 25, § 90.4

April ninth of each year is hereby established as "Prisoners of War Remembrance Day" in Oklahoma. The sacrifices of those persons who suffered captivity in foreign lands while in the service of their country shall be commemorated on this day. All citizens of this state are requested to devote some portion of Prisoners of War Remembrance Day to solemn contemplation on the plight of the men and women of this country who have been held prisoners of war. Teachers and students of the schools of this state are requested to observe the day with appropriate exercises.