[tz] [PROPOSED] Merge timezones that are alike since 1970

[Paul Eggert]

On 5/29/21 3:14 PM, Brian Inglis via tz wrote:

> Some(/many?/most?) downstreams maintain their own copies of older code 
> and data and cherry pick updates to maintain maximal backward 
> compatibility to avoid breaking their customers production systems, 
> generating bug reports, that costs them effort, time, and money to deal 
> with.

Yes, when we removed the SystemV/* names a couple of decades ago, some 
suppliers kept them around for awhile for compatibility reasons. I doubt 
whether that'd be useful for the current change, though, as it's a 
smaller change from the user viewpoint.

> If we keep the rules for regions common, but have similar zones for 
> different political entities at similar longitudes, we can maintain a 
> balance, and still reduce effort.

I'm not so much worried by the technical effort of maintaining Sweden 
data separately now, as by the political effort of justifying why we 
treat Sweden differently from Kosovo or any number of similar candidates 
in the future. Saying "we've always done it that way" is not sufficient 
justification for a political decision.