You do not need to schedule a tour in advance. The current interpretative bus tour departs continuously from the cemetery's Welcome Center. The hours of the tours are from 8:30 a.m. to 6:00 p.m., April through September, and between the hours of 8:30 a.m. to 4:00 p.m., October through March. Although tickets may be purchased in advance through www.arlingtontours.com, tickets may also be purchased at the Welcome Center ticket booth and at shuttle stops.