younger Easterners, who were subject to a system of labour and employment, which demanded that almost everybody work in the Eastern command production system. On 2 December 1964 East Germany, always short of hard currency, decreed that every Western visitor had to buy a minimum of 5 Eastern Mark der Deutschen Notenbank per day (MDN, 1964–1968 the official name of the East German mark, to distinguish it from the West Deutsche Mark) at the still held arbitrary compulsory rate of 1:1. The 5 marks had to be spent, as exporting Eastern currency was illegal, which is why importing it after having bargained for it at the currency market at Zoo station was also illegal. Western pensioners and children were spared from the compulsory exchange (officially in , i.e. minimum exchange). Not long after East Germany held the first cash harvest from the new compulsory exchange rules by allowing West Berliners to visit East Berlin once more for a day during the Christmas season. The following year, 1965, East Germany opened the travelling season for West Berliners on 18 December. In 1966 it opened for a second harvest of Western money between the Easter (10 April) and Pentecost (29 May) holidays and later again at Christmas. The situation only changed fundamentally after 11 December 1971 when, representing the two German states, Egon Bahr from the West and Michael Kohl from the East signed the Transit Agreement. This was followed by a similar agreement for West Berliners, once more allowing regular visits to East Germany and East Berlin. After ratification of the Agreement and specifying the relevant regulations, West Berliners could apply for the first time again for visas for any chosen date to East Berlin or East Germany from 3 October 1972 onwards. If granted, a one-day-visa entitled West Berliners to travel to the East until 2 am the following day. The visitors were now spared the visa fee of 5 Western Deutsche Marks, not to be confused with the compulsory exchange amounting to the same sum, but yielding in return 5 Eastern marks. This financial relief did not last long, because on 15 November 1973 East Germany doubled the compulsory exchange to 10 Eastern marks, payable in West German Deutsche Marks at par. One-day visas for East Berlin were now issued in a quickened procedure; visas for longer stays and visas for East Germany proper needed a prior application, which