September 1

Regarding children: at fifteen a Bahá'í is of age as far as keeping the laws of the Aqdas is concerned -- prayer, fasting, etc. But children under fifteen should certainly observe the Bahá'í Holy Days, and not go to school, if this can be arranged, on these nine days. 
- Shoghi Effendi  (From a letter written on behalf of Shoghi Effendi to the American National Spiritual Assembly, dated 25 October 1947; included in a letter from the Universal House of Justice to National Spiritual Assemblies, dated 28 January 1966; ‘Messages from the Universal House of Justice 1963-1986’)