MESZ

MESZ stands for Mitteleuropäische Sommerzeit, which is German for Central European Summer Time. It is the daylight saving time observed in many European countries that use the Central European Time (CET) zone during standard time. Because of the change to longer daylight hours, the clocks are set forward by one hour from the usual UTC+1 offset, resulting in a UTC+2 time zone during the summer months.

The practice of using MESZ originated in World War I as a measure to conserve coal and other resources. Since then, the summer time convention has been adopted and abandoned by various nations several times before becoming standardized. In 1980, the European Economic Community established a unified system, setting the dates for the clock changes. Under this system, clocks go forward at 02:00 local standard time on the last Sunday in March and go back at 03:00 local daylight time on the last Sunday in October. Most European Union members currently observe MESZ, but a few opt out.

MESZ is commonly referenced in international scheduling, travel itineraries, and aviation timing systems. When converting between standard and daylight times, locations that normally observe CET will add one hour. For example, Berlin is listed as CET/UTC+1 during winter and as MESZ/UTC+2 during summer. The abbreviation MESZ is mostly used in German-language media and documentation, whereas English-language outlets often use CEST for Central European Summer Time. Consistency in notation is important for global coordination and to avoid confusion when scheduling events across time zones.