Mo. Rev. Stat. § 9.169: Random Acts of Kindness Day designated for August 31.

August thirty-first each year shall be known as "Random Acts of Kindness Day" in Missouri to mark the beginning of suicide prevention awareness month in September. The citizens of this state are encouraged to celebrate this day by engaging in random acts of kindness toward their fellow citizens and remembering that one small act of kindness has the power to change the course of a person's life and the potential to impact countless lives as random acts of kindness are paid forward.