The switch to daylight savings time

[Guy Harris]

>Arthur David Olson a couple of years ago posted an implementation of
>the standard time conversion functions that was driven by external
>table files, which allow for easy incorporation of new time zone rules.
>For unknown reasons, AT&T appear to have settles on a kludgier approach
>for their implementations.

S5R4 includes the Olson implementation (as well as the kludgier stuff,
for backwads-compatibility and, alas, POSIX compatibility); I don't know
how heavily they advertise that fact, or support it in any whizzo system
administration front-end (e.g., they may tell you to set TZ up as
"EST5EDT" or some horrible POSIX-style "include the rules in the string"
setting, rather than as "US/Eastern").