[tz] TZDEFRULESTRING is increasingly out-of-date

Tom Lane tgl at sss.pgh.pa.us
Sun May 7 19:23:03 UTC 2017

Due to a script's unintended failure to supply a -p option to zic,
I recently had my nose rubbed in the fact that localtime.c still
has this as the fallback when the "posixrules" link can't be loaded:

** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
** We default to US rules as of 1999-08-17.
** POSIX 1003.1 section 8.1.1 says that the default DST rules are
** implementation dependent; for historical reasons, US rules are a
** common default.
#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#endif /* !defined TZDEFDST */

It's now over ten years since the US last followed those rules;
isn't it time to update TZDEFRULESTRING to match current law?
I can't really think of any situation where the current default
would be of any value now.

Apologies if this policy is being followed intentionally;
but I couldn't find any discussion of the point by googling.

			regards, tom lane

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