On Wed, Nov 30, 2016 at 10:18 AM, Andrey Semashev <[email protected] > wrote:
> On 11/30/16 21:02, Marshall Clow wrote: > >> On Wed, Nov 30, 2016 at 9:15 AM, Andrey Semashev < >> [email protected]> >> wrote: >> >>> >>> https://github.com/boostorg/date_time/pull/29 -- switch +/- on parsing. >>> >>>> Definitely correct, will break code. >>>> >>>> >>> I think we should fix bugs even if it breaks code. We could try to make >>> it >>> less painful though. >>> >> >> >> I'm really reluctant to make this change. I see it breaking lots of >> people's code for a small benefit. >> >> Short synopsis: >> There are two ways to describe a timezone difference from GMT (only two? >> You must be mad! - Ok, two in this instance). >> >> * Going west is negative. This reflects the fact that the time "gets >> earlier" as you go west. In this scheme, San Diego is GMT-8, or "8 hours >> behind GMT". When it's 8 AM in San Diego, then it's 4 PM in London. This >> is >> what the ISO specifies. In my experience, this is what I see when people >> want to use time zones. >> >> * Going west is positive. This reflects the "amount of time that needs to >> be added to the local time to get to GMT. In this scheme, San Diego is >> GMT+8. This is what Posix specifies. >> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html >> >> Boost.DateTime has a call named posix_time_zone >> > > to_posix_string? Yes, you're correct - my internal auto-correct misfired. > but it implements ISO time zone semantics. >> >> I asked Jeff Garland about this a while back, and he was horrified at the >> idea of breaking everyone's code for this. His response was "Change the >> docs, don't break code" >> > > Thing is, the function have POSIX in its name, so POSIX semantics is > implied. Agreed. But people seem to have dealt with this inconsistency already (for more than a decade) > Maybe we should create a new function and deprecate to_posix_string? The > new function could take an argument to select the desired behavior. > > That could work. I just don't want to break the existing users. (I suspect there are many) -- Marshall _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost-maint
