Re: [boost] [date_time] Time zone improvements

Subject: Re: [boost] [date_time] Time zone improvements
From: Rutger ter Borg (rutger_at_[hidden])
Date: 2011-04-22 03:58:17

On 2011-04-21 18:17, Luke Camden wrote:

> Hi all,
>
> Apologies for digging up the past, but did this lead to anything? Did
> time_zone_base prove to be an adequate abstraction in this case?
>
> Best regards,
> Luke
>

Hey Luke,

unfortunately my work didn't lead to anything yet except for having 
implemented the ability to read and use the binary format of the 
timezone database files (both the 32 and 64 bit parts).

time_zone_base has a couple of presumptions which prevent a correct 
implementation of the Olson database:

1) dst_local_start_time / end_time assumes one such event per year (may 
be less or more in time zone transition years / countries that don't do 
DST). A correct interface should assume a series of zone transition 
points (usually two per year for a given area/location).

2) all *zone_name, *zone_abbrev functions should be a function of time, 
i.e., it needs a ptime parameter. The zone naming may change over time 
(e.g., if a country changes their time zone).

Cheers,

Rutger