Brazil rule issue

[Alain Petit]

Hi

Thank you for the explanation, this will help my understanding a lot.

-Alain



-----Original Message-----
From: Olson, Arthur David (NIH/NCI) [E] [mailto:olsona at dc37a.nci.nih.gov] 
Sent: Monday, November 24, 2008 5:07 PM
To: tz at elsie.nci.nih.gov
Cc: Alain Petit
Subject: RE: Brazil rule issue

The differing years on the "max" lines are correct--or, in any event, as correct as can be for now.
Since there are two transitions a year--one to DST and one from DST--we do expect two "max" lines.
Starting in 2008, Brazil always goes in to DST on the third Sunday of October; thus the "Oct Sun>=15" line.
Improvidently, the end of DST is legislated to avoid coinciding with Carnaval; the end of DST is deferred a week if it would fall during Carnaval.
So the ending ("Feb") rules need to be done on a year-by-year basis (or at least a year-range by year-range basis), accounting for the plethora of "Feb" rules.
The cases are specified through 2038 (the maximum year associated with a signed, 32-bit time_t value).
After that (through year "max") the rules say that DST ends the third Sunday of February every year; this is wrong by a week in some cases but is better than nothing.

We could get things right using the "yearistype" mechanism; there has already been some grumbling about the advisability of doing so.

				--ado

From: Alain Petit [mailto:ALAIN.PETIT at oracle.com] 
Sent: Monday, November 24, 2008 4:23
To: tz at lecserver.nci.nih.gov
Subject: Brazil rule issue

Hi
 
I am looking in the Brazil rules and I was wondering if this was expected:
 
<snapshot>
 
Rule    Brazil  2007    only    -       Oct     Sun>=8   0:00   1:00    S
# From Frederico A. C. Neves (2008-09-10):
# Acording to this decree
# <a href="http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2008/Decreto/D6558.htm">
# http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2008/Decreto/D6558.htm
# </a>
# [t]he DST period in Brazil now on will be from the 3rd Oct Sunday to the
# 3rd Feb Sunday. There is an exception on the return date when this is
# the Carnival Sunday then the return date will be the next Sunday...
Rule    Brazil  2008    max     -       Oct     Sun>=15 0:00    1:00    S
Rule    Brazil  2008    2011    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2012    only    -       Feb     Sun>=22 0:00    0       -
Rule    Brazil  2013    2014    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2015    only    -       Feb     Sun>=22 0:00    0       -
Rule    Brazil  2016    2022    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2023    only    -       Feb     Sun>=22 0:00    0       -
Rule    Brazil  2024    2025    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2026    only    -       Feb     Sun>=22 0:00    0       -
Rule    Brazil  2027    2033    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2034    only    -       Feb     Sun>=22 0:00    0       -
Rule    Brazil  2035    2036    -       Feb     Sun>=15 0:00    0       -
Rule    Brazil  2037    only    -       Feb     Sun>=22 0:00    0       -
# From Arthur David Olson (2008-09-29):
# The next is wrong in some years but is better than nothing.
Rule    Brazil  2038    max     -       Feb     Sun>=15 0:00    0       -

</snapshot>
 
 
There is 2 'max' entry for Brazil, one for 2008, and one for 2038.
Rule    Brazil  2008    max     -       Oct     Sun>=15 0:00    1:00    S
Rule    Brazil  2038    max     -       Feb     Sun>=15 0:00    0       -
Reading the entries for 2012+ I feel that the one for 2008 should be a 'only' rather than 'max'.
 
Is that correct?
 
Thanks
Alain Petit