26th June 1945

Mi.7 - the stamp is from the American printing, available throughout the Bizone from the date of issue until counter sales stopped in mid 1946, and it was valid until 31st October 1946 in the American zone and 7th November 1946 in the British zone (the references in Michel to availability and validity in Berlin are specific to that city).

This is a very early date as letter post only resumed in RPD Hannover on 20th June 1945.