[tz] Asia/Tomsk

[Matt Johnson (PNP)]

> Windows uses abbreviations like RTZ6 for Russian timezones.

We removed those in April's update.
https://support.microsoft.com/en-us/kb/3148851
https://blogs.technet.microsoft.com/dst2007/2016/03/15/time-zone-updates-for-russia/

Basically, someone (not me) thought it would be a good idea to number the zones - but it became apparent later that it just added to the confusion because there were some Russian zones with numbers and some without them.  We added more with the recent zone splits, so they really don't make sense for us.

> Maybe tzdata should adopt those abbreviations...

If they were, more than one IANA zone might be sharing the same RTZ number, and that still doesn't address the periods when DST was being used.

Also, since the number of zones has changed over the years, it would be really weird to see RTZ11 during a period when there were only 9 zones.  (See https://en.wikipedia.org/wiki/Time_in_Russia )

I'm not sure what the answer is, but I recommend against using RTZ# style abbreviations.

Matt Johnson
Microsoft