Mo. Rev. Stat. § 9.137

The second Friday in March shall be set apart and designated as "Missouri School Read-In Day". It is recommended to the people of the state that the day be appropriately observed through activities that will bring about an increased awareness of the importance and benefits of reading and encourage greater emphasis on reading, both in the school and in the home. Missouri school read-in day recognizes that reading proficiency is a major factor in determining a child's success in school, regardless of the socioeconomic status, race, ethnic background, or educational level of the child and the child's family.