Summer time was first introduced by the Central Powers. Checking the German Wiki and this ultimate source I just found, it was six weeks before France, but it was short-lived, and resurrected during the next fuel shortage: the next world war... and then lasted till 1949. In 1947, there was even a "High Summer Time", two hours ahead!... Reintroduction in 1980 was EC-inspired. The war-time German Summer Times differed each year, but generally April to September/beginning of October, post-oil-shock it was end of March to end of September, then with the 1996 EU standardisation the end was moved one month later (I remember this, the same change affected Hungary).

_{*Lunatic*, n.
One whose delusions are out of fashion.}