5-1-2017 Patients, Doctors, and Rangers Brave Weather on National Park Rx Day On April 23, the Kids in Parks program joined the National Park Service, National ParkRx initiative, and several other park prescription programs from across the country in celebrating the second annual National Park Rx Day. The annual ceremony takes place on the last day of National Park Week, and doctors nationwide prescribe the events to their patients to get them active outdoors and connect them with the health benefits associated with spending time in parks.