id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
4545,Invalid posix timezone format,Roland Bock <rbock@…>,az_sw_dude,"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
",Bugs,new,To Be Determined,date_time,Boost 1.44.0,Problem,,,