IIRC we had DBST during WW2 to aid productivity.
. . . and we had a test of DBST for the summer and BST for the winter in the late 1960s. At the end of that experiment, the answer was a big
NO. Since that 1960s experiment, I have
never, ever adjusted my watch twice a year -- it remains permanently on UTC (i.e. GMT)!
If someone desperately wants to be on eastern
French time, just move there.
Nothing is gained or lost by this incessant, twice yearly, palaver. The sun will "rise" and "set" in the sky regardless of what the foolish wish to call the current time. The length of daylight will not change, it will follow the natural annual cycle.