Also called summer time, DST is the practice of moving the clocks forward a certain amount of time from standard time for the purpose of saving energy through more efficient use of the daytime in the summer. DST is primarily used in countries in temperate regions where the amount of sunshine varies greatly depending on the season. The start date of DST varies from country to country. Suprema's BioStar and devices support a DST option, which allows administrators to manually set the start date and end date for DST.