Re: [boost] [date_time] recommending upgrading the timezone database

Subject: Re: [boost] [date_time] recommending upgrading the timezone database
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2018-01-07 23:50:09

On 7/01/2018 05:49, James E. King, III wrote:
> The timezone database in Boost.DateTime doesn't have enough information in
> it to be accurate all the time.  For example if a region changes time zone
> rules, when applying timezone only the current rule will be applied
> regardless of the date involved.  If a region stops using daylight savings
> time, but a date/time falls before that rule change, it should still use
> daylight savings in printed output, correct?
> 
> The IANA timezone database is more complete, and we could switch
> Boost.DateTime to use that instead.  It is also maintained more frequently
> than the built-in one, which was last updated 7 years ago, and 4 years
> before that.
> 
> Any thoughts on this?
> 
> https://github.com/boostorg/date_time/issues/67

I recently came across these:
   - http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0355r0.html
   - https://github.com/HowardHinnant/date

While they're based around C++11+ and chrono rather than DateTime, they 
do include support for the IANA timezone database; either downloaded, 
shipped-with, or using the OS's copy.

Perhaps you could coordinate with him to include similar functionality 
in DateTime, or to bring his library into Boost as a suggested C++11 
replacement for DateTime (or everyone could just wait for C++20...)?