See Also |

## Bibliographical References

| Object-Oriented Applications, by B. Meyer and J.M. Nerson (editors). Prentice Hall, 1993. ISBN 0-13-013798-7. Written by a group of experienced project leaders of successful O-O developments, this book studies actual Eiffel projects in depth. Chapter 2, entitled Temporal Software Components, was written by Ted Lawson, Carmel Balthazaar and Alex Gray of the University of Wales in Cardiff. It includes a comprehensive presentation of the notions of time, duration, interval and date. The classes described in this chapter are available in the Cardiff Date/Time cluster.

## Related Resources

The Eiffel Zone Software Directory contains many links to Eiffel libraries sorted by category. Also of interest is the Cetus Links Eiffel page and its library section which provides links to open-source and commercial date/time libraries.

ISE's EiffelTime provides a large set of mechanisms for handling date and time properties. Its design resulted from a study of many available date and time libraries, including the time and date cluster of EiffelStore (ISE's multi-platform, multi-DBMS database library), the Cardiff library as described by Ted Lawson in the book Object-Oriented Applications, and all other known Eiffel date and time libraries.

The Cardiff Date/Time cluster, written by Christine Hollinshead for TowerEiffel and ported to ISE Eiffel by Peter Webb, is designed to support the creation and manipulation of dates and times within the Gregorian calendar system. It is made up of the classes described by Ted Lawson in Object-Oriented Applications. This library is copyrighted by the University of Wales College of Cardiff.

SiG (now Object-Tools) Date/Time Cluster is a date and time library for Visual Eiffel, ISE Eiffel and SmartEiffel. It provides timestamp classes (absolute values) and duration classes (differences between two timestamps). This library is delivered under the GNU license and can be downloaded from the Eiffel Zone Software Directory. It is also included in Visual Eiffel standard distribution.

Pylon is a small, portable, freeware Eiffel library for data structures and other basic features such as date and time classes that can be used as a foundation library by more ambitious or specialised Eiffel libraries. Pylon is a copyrighted freeware developed by Franck Arnaud. It can be downloaded from the Eiffel Zone Software Directory.

## Acknowledgements

Most ideas used throughout the design of the Gobo Eiffel Time Library come from other existing date/time libraries, such as EiffelTime from ISE and Temporal Software Components from Ted Lawson in Object-Oriented Applications.