There are three new TZIDs added in 2013a:
Add these 3 zones as canonical zone.
Note: All of these 3 location do not have matching LOCODEs. By the policy, 5-letter short time zone IDs are coming from LOCODE. If a short ID is not from LOCODE, we must use 3-4 or 6-8 letter code. These zones associated with specific locations and I don't think there are any political dispute for these locations. Therefore, I'm proposing to use 2-letter country code for the first two letters. By doing so, it's easier to understand and they align well with other zones in same countries.
Khandyga (Tomponsky District of the Sakha Republic, Russia) -> rukhndg (7 letters)
Ust-Nera (Oymyakonsky District of Sakha Republic, Russia) -> ruunera (7 letters)
Busingen (Büsingen am Hochrhein, An enclave of Germany surrounded by Switzerland's territory) -> debsngn (7 letters)
There is no need to add any new metazones for these time zones. The mapping data for them will be:
Europe/Berlin used to be a single zone for Germany. With the addition of Europe/Busingen, this is no longer true. Busingen is a relatively small village within Switzerland region, so obviously Europe/Berlin is the dominant zone for Germany. For better "country" based location name construction, we also should put Europe/Berlin as primary zone of Germany:
We also need Windows zone mapping. The Windows mapping is based on current offset (Windows does not support historic rules before 2005). The mapping data version should be also updated to 2013a. The changes are: