Advent, Advent . . . this is your picture for December 17. This was a very important day for Berliners for a number of reasons. On December 17, 1963, the government of the German Democratic Republic and the West Berlin Senate agreed on the Passierscheinabkommen, ratified with the four Allies who governed Berlin. The Passierscheinabkommen made it possible for West Berliners to go to the Eastern part and visit their relatives. Until then, traffic had been cut off by the Wall since August 1961. This was a huge Christmas present for Berliners.
The first crosspoint to open was Oberbaumbrücke, the bridge crossing the Spree, but only for foot traffic. Cars as well as the subway were still suspended.
Nine years later, on December 17, 1972, the Transitabkommen was signed. This allowed Germans to drive from West Germany to West Berlin while transiting through the GDR without (much) border controls. Everybody does remember the words spoken by border guards, "Do you have children on board? Weapons?"