World Clock

World Clock


This module allows to calculate the current time in another location (related to a specific location). Not only different time zones, but also summer and winter time (if available) are taken into account. In addition, it is shown whether and what kind of public holiday takes place at the respective location.


It is chosen as the location "Hamburg" and as the comparative location "Los Angeles". The time zone difference here is 9 hours. If "4.7.1996" is now selected as the date and "17.00" as the time, the time difference remains unchanged, as daylight saving time applies in both countries. This means that the clock of the place of comparison shows "8.00 o'clock". It also indicates that this day is a public holiday in "Los Angeles", namely "Independence Day".


Selection of a location

When the application is started, the location currently set on the system is determined and transferred to the field for the own location. All available countries are entered in the field for the comparison location. To select another location, open the box and click on another location. Only locations that belong to the same superordinate location are available for selection. If, on the other hand, a subordinate or superordinate location is to be selected, the arrow keys are to be used. If one of the buttons is not available, this means that no superior or subordinate location exists.


Los Angeles" is to be selected as the reference site. First, open the User Box to display the list of available countries in the comparison location field. Now "USA" can be selected. To get to the state level of the USA press the arrow key". Opening the box again will list all (available) states of the USA. After selecting "California" and pressing" again, all counties/cities of California are displayed. From this list, "Los Angeles" can now be selected.

Exceptional case:

In the case of locations that extend over several time zones (e.g. the USA), the corresponding clock disappears because no time zone is clearly selected. A message indicating this appears in the status bar at the bottom of the window. After selecting a location that is located in only one time zone, the corresponding clock is displayed again.

Selection of a time

The application does not necessarily refer to the current time, but makes it possible to specify any time. In this way, questions such as "If I am in London at 15.00 on 7.9.96, what time is it in New York, and is it a public holiday in one of the two places?" can be answered.

To change the time, simply set a new time in the corresponding fields for the time and date. If you want to set the current time or date again, press the corresponding button.

consideration of summer and winter time

The application takes into account the changeover time to summer or winter time at a location. If, for example, the time difference between "Hamburg" and "Los Angeles" is calculated on "1.2.96", it is 9 hours, but on "1.4.96" it is 10 hours, since on this day in Germany it has already been changed to daylight saving time (one hour ahead), but not yet in the USA.

The time valid at the respective location is displayed ("summer time", "winter time"). If the time is not changed at that location, this is indicated by "normal time".

Display of public holidays

For each of the two locations, it is shown whether there is a public holiday at that location at the time shown for that location.

Field Description
Own location Select your own location
new time Set the time
current date Set date
Phone number  
Place of comparison Select comparison location
Date Calculated date
button Description
current time comparison time is set to the current time
current date comparison date is set to the current date


Related topics


Technical Documentation

World Clock Module

The core of the "World Clock" consists of the calculation of the difference between two global dates, i.e. dates that also have a time zone specification. The class CX_GLOBAL_TERM is available for this purpose. When calculating the time difference between two locations, however, an existing summer and winter time should also be taken into account. This information is kept in the location data as a periodic date in form of an object of the class CX_PERIODIC_DATE. This means that the date of the summer time changeover does not have to be specified for each year, but is held as a formula. In Germany, for example, the changeover to summer time is usually made on the "last Sunday in March". The exact changeover time for a particular year is returned by the system as an object of class CX_TERM.

Of course, the starting point does not have to be the same as your own location. To access data from a specific location, it only needs to be stored in an object of the classes CX_LOCALE, CX_STATE_LOCALE or CX_COUNTRY_LOCALE to allow access. Even a (temporary) exchange of the system location with another location is no problem. In this way it can be determined whether a holiday is taking place at the comparison location.

Module name





In addition to restricting access rights via the class and its data fields, the module can be restricted in its use via some of the received messages.

Received messages
Message Parameters Function Security


Sent messages
Message Parameters Function Receiver module

Operational business