Question on interpretation of rules intervals

[Liviu Nicoara]

Ahh -- obviously. Thank you all.

Olson, Arthur David (NIH/NCI) [E] wrote:
> Starting in 1942, the U.S. observed Daylight Saving Time year-round as
> part of a war-time effort to conserve energy; rather than being called
> "Standard" or "Daylight" time, it was called "War" time (as in "Eastern
> War Time").
> 
> WWII ended during the summer of 1945, when Daylight Saving Time would
> normally be observed; folks started using "Peace" rather than "War" in
> time zone names (such as "Eastern Peace Time").
> 
> When the normal "fall back" date arrived in 1945, folks reverted to
> "Eastern Standard Time" (and to "Eastern Daylight Time" in 1946).
> 
> So...there's one rule in 1942 to get things on to "War" time (in effect
> through 1945, with no clock changes), one rule in 1945 to get things on
> to "Peace" time, and one rule in 1945 to "fall back" to standard time.
> 
> 				--ado
> 
> -----Original Message-----
> From: Liviu Nicoara [mailto:nicoara at roguewave.com] 
> Sent: Monday, April 02, 2007 10:17 AM
> To: tz at lecserver.nci.nih.gov
> Subject: Question on interpretation of rules intervals
> 
> Hi all,
> 
> I have a question about how to interpret the US set of rules. After 
> going through the "zic" man page and the mailing list archive I am still
> 
> unclear about the meaning of using this:
> 
> [...]
> Rule US 1942 only - Feb  9 2:00   1:00 W # War
> Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
> Rule US 1945 only - Sep 30 2:00      0 S
> [...]
> 
> in a zone definition like this:
> 
> Zone America/New_York -4:56:02 -  LMT  1883 Nov 18 12:03:58
>                        -5:00   US  E%sT 1920
>                        -5:00   NYC E%sT 1942
>                        -5:00   US  E%sT 1946
>                        [...]
> 
> As I see it, the US rule has a transition in 1942 (only), on Feb 9th, 
> where it saved 1 hour. Am I correct in interpreting the gap of 43-44 as:
> 
> 1. The transition of 1942 was observed up until 1945, Sep 30th, and...
> 2. The entry for Aug 14th, 1945 transition exists only in order to be
>     used in time zones which did not observe the 1942 transition?
> 
> Thanks,
> Liviu
>