Daylight saving time (DST), also known as daylight savings time or daylight time (the United States and Canada), and summer time (United Kingdom, European Union, and some others), is the practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time. The typical implementation of DST is to set clocks forward by one hour in the spring ("spring forward") and set clocks back by one hour in autumn ("fall back") to return to standard time. As a result, there is one 23-hour day in late winter or early spring and one 25-hour day in the autumn.