Daylight Saving Time(DST) : DST is the practice of advancing clocks during part of the year, typically by one hour around spring and summer , so that daylight ends at a later time of the day. How SAP systems are affected due to DST : Many kinds of software that deal with local time, such as the SAP system, have serious problems in this hour, because operations which use local times can fail if time does not increase continuously, and points in time can "happen" twice. Double Hour Concept : In many northern hemisphere countries (i.e., Europe: European Union, Russia; North America: USA, Canada, Mexico) At the end of daylight-saving period, one hour occurs twice as the clocks are put back an hour. In Europe, for example, this hour is between 2:00 a.m. and 3:00 a.m., whereas in the USA it occurs between 1:00 a.m. and 2:00 a.m. This means that the clock will move twice in the same day from 1am to 2am. Double hour refers to the duration of the hour that the cloc