Tonight, Bulgarians will adjust their clocks backward by one hour as the country returns to winter astronomical time. At 4:00 a.m., clocks will be set back to 3:00 a.m., marking the official end of daylight saving time for the season. Astronomical time will remain in effect until March, aligning daily schedules more closely with natural daylight.

The practice of moving the clocks was first introduced in Europe in 1976 at France’s initiative. Bulgaria adopted daylight saving time in 1979, and since a 1997 decree, summer time begins at 3:00 a.m. on the last Sunday of March. The concept itself dates back to 1784, when Benjamin Franklin suggested in a Paris Journal letter that Parisians could save resources by waking and sleeping earlier. Germany implemented it during World War I to conserve fuel, followed by Britain and the United States.

For ordinary Bulgarians, tonight’s shift means an extra hour of sleep, but experts warn that even this seemingly small adjustment can affect the body. The change slightly disrupts the circadian rhythm: the internal clock controlling sleep, alertness, hormone production, and mood. While most people adapt quickly in autumn, some may feel groggy, have difficulty waking, or experience mild sleep disruptions over the next few days.

Parents, in particular, should anticipate minor adjustments for children, whose routines may be temporarily affected. Experts advise using the extra hour for genuine rest, avoiding late-night activities, and maintaining consistent sleep patterns to minimize disruption.