At the beginning of the series, the Galactica arrives at Earth in the year 1980. It is said by Adama that their voyage has taken 30 years which means that the events of Battlestar Galactica took place around 1950 in Earth time. However, at the very end of the original series (in the episode "The Hand of God"), the Galactica receives a television transmission that shows the 1969 Apollo moon landing. Since the fleet's journey to Earth had only started a few months prior, it means that the events of Battlestar Galactica must have taken place at least in the late 1960s Earth time.