Timezone databases: feedback on the draft

[dkhalanskyjb]

There is a pull request with the updated timezone interface: #610
This is a place for discussing the concepts behind the changes, raising concerns about the proposed API, asking questions, making suggestions, etc.

[corneil]

I want to understand the need for 'custom timezone databases'
We use anything else than IANA database with all current and history data?

[dkhalanskyjb]

Usually, you shouldn't need anything other than the up-to-date IANA timezone database or the one shipped with the system. The use cases we've found in the wild were limited to these two, and the proposed PR should cover them.

Our users described several other variants they would be interested in:

• Obtaining the timezone information from the server lazily, when requested.
• Testing code against different versions of the timezone database: one current, the other containing some proposed future changes to a timezone.
• A timezone database that can be updated without restarting the JVM.