Spring Forward, Fall Back -- but not just yet

Monty Solomon monty at roscom.COM
Sun Oct 6 18:56:42 UTC 1996

Excerpt from RISKS DIGEST 18.50


Date: Tue, 1 Oct 1996 12:02:10 +0200
From: minow at apple.com
Subject: Spring Forward, Fall Back -- but not just yet

The biannual daylight savings time confusion began this weekend in Sweden.
When Sweden joined the EU (Common Market), it changed the fall changeover
from the last weekend in September to the last weekend in October to conform
with the rest of Europe.

Unfortunately, a few hundred thousand Windows '95 machines were not
informed of the changeover and, followed pre-programmed instructions,
switched on the old schedule.

This is, of course, one small example of a much more difficult problem:
there is no obvious way to pre-program daylight savings time changeover
in a way that is sufficiently robust to withstand government intervention.
(My favorite example is Arizona, where federal land changes, but state
land remains on mountain standard time year around.)

Martin Minow minow at apple.com


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