1963, 'West Meets East.' Two Brothers Separated By The Berlin Wall Finally See Each Other Again After 'Border Pass Agreement' (Colorized)

Refugees Were Flooding West Berlin Before The Wall Went Up
Two years after the Berlin all went up to keep the citizens of East Germany from fleeing to the West, there was a brief change in the relations between the two halves of Berlin. On December 20, 1963, the Berlin Wall opened for the first time and allowed thousands of Berliners from the west to travel to East Berlin and visit their friends and family.
Lasting for 18 days until January 1964, the brief change in the rules was only applied to those from West Berlin. No one from the East was allowed to make the trip. Still, it was a happy occasion for those men and women who hadn't seen hide nor hair of their relatives since the wall went up in earnest.
This opening of the Berlin Wall, no matter how brief, provided a brief respite from the ramping up of the Cold War and the constant fear of being shot in an attempt to escape to the West.

Prior to the construction of the wall in 1961, thousands of refugees from East Berlin were crossing into West Berlin creating a massive immigration problem. President Kennedy wasn't excited about the wall, but he felt that it was better than going to war over the immigration issue. As the wall went up people had to choose where they'd live without knowing if they'd ever be able to see their friends and family again. The West may have offered freedom but it was a freedom without family, while the East offered a better chance to live with your family but came with the possibility of death for anyone who tried to leave.
It wasn't unheard of for someone to escape from East Germany. People jumped out of windows near the wall and jumped over, and one guy even flew a hot air balloon over the Wall. That was in 1979, so let's back up to 1962 when the two fellows in this photo were able to embrace for the first time in years.
Merry Christmas (Wall Is Over)

Negotiations between East and West Berlin resulted in a Christmas reprieve in 1963. Agreement was reached stating that from December 20 to January 5, 1964, West Berliners could apply for one-day visas that allowed them to visit their relatives on the other side of the wall. In just over two weeks more than 170,000 one day visas were issued to the people of West Berlin. There were no passes granted to people living in East Berlin.
CNN reports that around 2 million West Berlin residents applied for holiday passes, meaning that the people were able to score passes only received one. There were no two day holidays in East Berlin, at least not in 1963.
East meets West

Stepping into East Berlin carried a mix of emotions for those who made a life for themselves outside of the Communist controlled walls of the city. The travelers were no doubt excited to see their friends and family, but they were also bombarded with propaganda from the moment they entered the city. Loudspeakers welcomed the citizens of West Berlin into “the capital of the German Democratic Republic,” and travelers were given pamphlets stating that the wall was constructed to “protect our borders against the hostile attacks of the imperialists.”
The propaganda machine didn't stop in East Berlin. The media in the West claimed that the travelers to the East were being used as pawns by the East. There was even a belief that communists were attempting to use this act of good will to ingratiate themselves with the west in order to gain a permanent foothold in Germany.
The only visitors allowed were family members

The propaganda on both sides of Berlin didn't overtake the Christmas cheer, but it was a low level thrum of white noise that couldn't be ignored. Everyone in both East and West Berlin realized that they were in the middle of a pot waiting to boil over. To gain a pass into East Berlin you couldn't just say that you are visiting a friend. The only people who received a pass across the Berlin Wall were those who had parents, children, or siblings living in East Berlin. Everyone else was out of luck.
Those who were able to visit East Berlin were overjoyed to see their family members. Many of them had been separated for at least two years, some of them even more. By the final day of the the wall opening up, there were thousands of people attempting to get a few hours with their families in before the wall closed for good.
1963 wasn't the last time the wall opened

The one-day visa system proved to work so well during the holidays of 1963 that East Berlin opened up its borders again for the next three Christmas seasons. In 1971, there was finally agreement that allowed West Berliners to apply for visas to allow them to travel to East Berlin regularly. Even though there was a standardized way to visit East Berlin, the existence of the wall made it impossible to forget the Cold War raging around them, and the antipathy held between the governments of East and West Berlin.