Thanks for the feedback. This is indeed an issue with the EiffelTime library. At the moment, we have to provide 3 configuration files for the 3 languages we support and users have to choose which configuration file they want to use. In your case, you will have to create your own configuration file which includes your version of DATE_TIME_TOOLS.

We are looking at rewriting the EiffelTime library so that one can provide a customized version of the DATE_TIME_TOOLS class without breaking existing code.