Paul Eggert <eggert@cs.ucla.edu> wrote on Mon, 5 Feb 2018 at 09:23:04 -0800 in <c968840d-014f-abdf-8efa-778c297039fc@cs.ucla.edu>:
Although it doesn't add value for today's timestamps, it is useful for historical timestamps that have been covered by the database for decades. Some applications do deal with older timestamps, and when it's easy (as it is here) it's helpful to correct longstanding data entry errors that were forced by an inadequate format.
I question this claim, that it is helpful to correct longstanding data entry errors. The result is that historical timestamps in such zones change, and interval times that may have been previously calculated may change, either becoming incorrect (or correct; or "differntly incorrect"). Those are not necessarily minor changes. We should pause before "correcting" historical timestamps, even if we think the change is better. (In practice, I suppose, we have been making changes willy-nilly to historical timestamps for long enough that anyone who cares has likely already been burned by it and adopted a solution to mitigate it, although what that looks like I am not sure. I'm not sure this is a great argument to keep doing so...) --jhawk@mit.edu John Hawkinson