This page has not yet been updated for Datebk6.
IMPORTANT: The material below does NOT come directly from CESD (the creator of Datebk). It is written by users of Datebk who are familiar with CESD's upgrade practices. You can get information from CESD himself at the Datebk website (e.g., to upgrade to Datebk5).
If you are a registered user of Datebk, you will not have to pay for upgrades to maintenance releases (e.g., upgrading from Datebk5 V-5.0 to Datebk5 V-5.1). Upgrading from one major release to another (e.g., Datebk5 to Datebk6 when Datebk6 is released) is usually not free because CESD puts a very large amount of work into new major versions to add a lot of new features. However, I believe that upgrading from Datebk4 to Datebk5 was free.
If you are a registered user of Datebk and have installed the English version, you can install a non-English version without re-registering (and vice versa of course).