Subject: [Boost-bugs] [Boost C++ Libraries] #4545: Invalid posix timezone format
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-08-16 16:28:00
#4545: Invalid posix timezone format
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Reporter: Roland Bock <rbock@â¦> | Owner: az_sw_dude
Type: Bugs | Status: new
Milestone: Boost 1.44.0 | Component: date_time
Version: Boost 1.44.0 | Severity: Problem
Keywords: |
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Hi,
I think that posix_time_zone in Boost.DateTime is using the wrong sign for
offsets from GMT:
According to the documentation, posix_time_zone is modeled after IEEE Std
1003.1. The documentation gives several examples, for instance
''"MST-7"''
''This zone is as simple as it gets. This zone lies seven hours west of
GMT and has no daylight savings.''
But all other sources for IEEE Std 1003.1 I found so far say that negative
offsets indicate '''east''' of GMT, see for instance:
http://www.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html
''If preceded by a '-' , the timezone shall be east of the Prime
Meridian; otherwise, it shall be west (which may be indicated by an
optional preceding '+').''
http://tools.ietf.org/html/draft-ietf-dhc-timezone-01
''The format of the IEEE 1003.1 POSIX timezone specification is defined
as follows:[...]If preceded by a '-', the timezone is east of the Prime
Meridian, otherwise it is west ('+' is optional)''
http://www.twinsun.com/tz/tz-link.htm
''Numeric time zone abbreviations typically count hours east of UTC,
e.g., +09 for Japan and -10 for Hawaii. However, the POSIX TZ environment
variable uses the opposite convention. For example, one might use
TZ="JST-9" and TZ="HST10" for Japan and Hawaii, respectively.''
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IMO, the implementation and/or the documentation should be changed.
Personally, I'd prefer a change in the implementation, even though this
would be a rather nasty breaking change.
Regards,
Roland
-- Ticket URL: <https://svn.boost.org/trac/boost/ticket/4545> Boost C++ Libraries <http://www.boost.org/> Boost provides free peer-reviewed portable C++ source libraries.
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