Don’t forget that clocks go back an hour overnight from Saturday to Sunday (officially at 0300 in the morning), meaning an extra hour sleep if you want it.
Daylight saving time is exactly that, moving clocks forward in the spring and then back again before the winter to make the most of natural daylight and so save energy. The initial idea comes from Benjamin Franklin in 1784, but it wasn’t introduced in most countries till the 1900s.
Daylight saving time was used in Slovakia between 1916-1918, then in 1940-1949, before being cancelled again for thirty years. It was reintroduced in 1979 and has been used here since.