[Boost-bugs] [Boost C++ Libraries] #4545: Invalid posix timezone format

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
--------------------------------------------+-------------------------------
 Reporter:  Roland Bock <rbock@…>           |       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.''


 ----


 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>
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