[tz] suggestion: split "backward" into "backward" and "deprecated"

[Paul Eggert]

On 5/4/20 8:06 PM, Andrew Gierth wrote:
>>>>>> "Paul" == Paul Eggert <eggert at cs.ucla.edu> writes:
> 
>  Paul> Getting back to the main point, I'm not sure it's worth
>  Paul> deprecating links like 'US/Pacific' any time soon, as so many
>  Paul> people use them
> 
> Are there any statistics on that?
> 
> The US/* names are one thing, but what about the nonsense like "W-SU"?

I don't know of any statistics. A quick Google search suggests that
TZ='US/Pacific' is far more common than TZ='W-SU'. That being said, I did find a
few instances of the latter, including:

http://forum.ixbt.com/topic.cgi?id=24:29252
https://github.com/rstudio/bookdown/issues/440
https://postgrespro.ru/list/thread-id/1220710