[tz] Relative to Beginning of Month or to End

Marvel, Jim (CPCOE) Jim.Marvel at honeywell.com
Fri Jul 6 18:10:11 UTC 2012

I see it in the Rules files now, like "europe".  Thanks also for the GNU-tip.

Jim Marvel

Software Engineer II 
Honeywell CMSS
8323 Lindbergh Court
Sarasota FL 34243
Phone - 941.360.6209 (alt: 941.360.6213)
Fax - 941.355.9241
jim.marvel at honeywell.com

>>-----Original Message-----
>>From: Paul Eggert [mailto:eggert at cs.ucla.edu]
>>Sent: Friday, July 06, 2012 2:01 PM
>>To: Marvel, Jim (CPCOE)
>>Cc: tz at iana.org
>>Subject: Re: [tz] Relative to Beginning of Month or to End
>>On 07/06/2012 08:55 AM, Marvel, Jim (CPCOE) wrote:
>>> Did a zdump.  How to tell if timezone DST rules indicate counting
>>> relative to beginning of month ("2nd Tuesday") or to end of month
>>> (last Sunday for example).
>>> Does this info live in the source code?
>>That info does not live in the data given to zdump.
>>It does live in the original source for that data, i.e., the source fed
>>to zic.  But zic discards it and it is not present in zic's output
>>(i.e., in zdump's input).
>>There is software that reverse-engineers the zic output and attempts to
>>infer that info.  It's not perfect, but it works fairly well in
>>practice, at least for future time stamps where there is typically only
>>one rule into the indefinite future.  See the function calendar-time-
>>zone-daylight-rules in GNU Emacs; there may be other examples but this
>>is the one I'm familiar with.

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