[tz] "non-standard" timezones

[Shawn Steele]

> Typically, I think, people use what is coming from the tz database, unchanged. 

> And in the exceptions, they typically edit an existing entry rather than come up with a new name.  
> And in the exceptions to *that*, they typically use a name similar to the names already
> in the database, rather than an unusual name.

That sounds logical, but are there *any* known cases where people make exceptions to the standard?  Even if they're reusing names?  Especially if they're reusing names?  (Reusing names for different behavior seems bad for interop).

-Shawn