In 1978, West Germany decided to reintroduce summer time, following the example set by several neighbouring states in the aftermath of the 1973 oil crisis. However, it only came into effect in 1980, after West and East Germany reached an agreement to observe summer time simultaneously from the last Sunday in March (02:00 CET) to the last Sunday in September (03:00 CEST). Thus both German states observed the same time until the German reunification in 1990, after which the reunified Germany retained the laws and thus also the Time Act ("Zeitgesetz") of West Germany.