51 Pa. Stat. § 20006
With respect to veterans of the World War, for the purpose of section three, in the case of members of the National Guard or the National Guard Reserve called into service by proclamation of the President, the time of service between the date of call into service, as specified in such proclamation, and the fifth day of August, one thousand nine hundred and seventeen, both dates inclusive, shall be deemed to be active service in the military or naval forces of the United States: Provided, That in case of members of the National Guard or National Guard Reserve called into the service by proclamation of the President before the sixth day of April, one thousand nine hundred and seventeen, active service in the military or naval forces of the United States, for the purpose of this act, shall be deemed to commence on the sixth day of April, one thousand nine hundred and seventeen.
51 P.S. § 20006