Dates and times of about 1650 cities around the world are displayed, and their daylight saving times (summer times) are updated automatically during the year. The calculations are based upon the user computer Datum and time. The user location is selected from a Datenbank of about 1400 cities of the world, representing all of the time zones or fractional time zones. The Datenbank contains about 300 [countries] for ease of query, eg. Wake Island is considered a country in the Datenbank.