24 Pa. Stat. § 15-1544
The Governor shall annually issue his proclamation, designating and calling upon the public schools of this Commonwealth to observe Free School Day in commemoration of the founding and development of free public schools within this Commonwealth. Free School Day shall be designated and observed each year between the dates of April first and April eleventh, both days inclusive. In pursuance to said proclamation of the Governor, appropriate exercises with respect to, and special study concerning, the founding and development of free public schools within this Commonwealth, and the recognition of the efforts and achievements of Honorable George Wolf, former Governor of this Commonwealth, Honorable Samuel Breck, former State Senator, Honorable Thaddeus Stevens, a member of the Legislature, relative thereto, shall be held in the public schools and other educational institutions within this Commonwealth.
24 P.S. § 15-1544