CET, or Central European Time, is a time zone that is 1 hour ahead of Coordinated Universal Time (UTC+1). It is commonly used in several countries in Europe, including Germany, France, and Italy. CET is observed during the standard time period, typically from the last Sunday in October to the last Sunday in March. During the summer months, many countries switch to Central European Summer Time (CEST), which is UTC+2. This change helps to make better use of daylight in the evenings. The transition to CEST usually occurs on the last Sunday in March, while the return to CET happens in late October.