[phobos] Status of std.gregorian

[Shin Fujishiro]

Jonathan M Davis <jmdavisprog at gmail.com> wrote:
> As for its design, it looks like it's holding the number of days as a ulong with 
> nothing more precise than that. I would have expected a time_t or equivalent 
> with the number of seconds or milliseconds since the epoch. So, that makes it 
> look like it doesn't care about anything more precise than days, which would be 
> insanely limiting if it's supposed to be replacing the buggy std.date.

I reckon the Date is pure date and time is supposed to be represented
by another type (not yet defined?).  I think that a pure date should be
represented by 24h time interval though.


> I'm not quite sure what the overall design plan is for std.gregorian, but due to 
> having to deal with various time-related issues at work, I'm 100% convinced that 
> the correct way to write time code is to have _everything_ in UTC until you 
> actually need it in local time, and at that point you do a conversion (likely to 
> a string); the time/date class however would _always_ be in UTC internally. I've 
> seen way too many timezone and DST issues to think that any other way of doing 
> it makes sense. time_t is always in UTC, though unfortunately most of the posix 
> functions (and likely Windows API functions as well) translate to local time 
> when converting time_t to anything else, which makes it quite easy to introduce 
> conversion bugs into code (especially when DST rolls around).

I agree.  UTC and local time must be different in types, or at least
timezone and DST information should accompany time data.


Shin