Both interpretation are correct and valid, it is just hard to capture them with
one class.
In normal human conversation and in the abstract, of course a date is just a
year/month/date triple. But that is because most people only look at this from
their own perspective. However, from an international perspective, of course it
must include time zone info. Remember end-of-year/new-year, with all those
articles about people in other countries partying or having fireworks
earlier/later.
Date transitions are different in each time zone, so to talk accurately about a
date, you need the context of a time zone.
Whether that timezone is actually part of the date object is another
discussion, but there is always the timezone context even if it is implicit
('of course I mean my own timezone and not yours').
> On 17 Nov 2017, at 14:19, Peter Uhnák <i.uh...@gmail.com> wrote:
>
> Because Date has, by definition, no concept of time.
> The only reason why you see it is because someone decided to save a bit of
> time and reuse implementation.
>
> If you want to move TZ, you need something that _has_ time. Such as
> DateAndTime.
>
> You can also read the comments ...
>
> Date
> > Instances of Date are Timespans with duration of 1 day.
>
> it represents an entire day, not a particular time point
>
> DateAndTime
> > I represent a point in time or timestamp as defined by ISO 8601.
> > I am TimeZone aware.
>
> I really don't understand why are you trying to force TZ into Date against
> it's purpose when you have a class that does exactly what you want and was
> built for that purpose.
>
> Peter
>
> On Fri, Nov 17, 2017 at 12:09 PM, Prof. Andrew P. Black <bl...@cs.pdx.edu>
> wrote:
>
>> On 17 Nov 2017, at 08:49 , Peter Uhnák <i.uh...@gmail.com> wrote:
>>
>> I find the concept of translating TZ of a Date silly. The real bug imho
>> should be that it prints both time and TZ.... this is Date, not DateAndTime.
>>
>
> I live in Oregon, and frequently work with people in New Zealand, which is
> (depending on the time of year) 19 to 21 hours ahead of Oregon. So, when it
> is 3pm at home, it is noon the next day in New Zealand.
>
> This means that in order to know the day of the week, the month, and even the
> year, of a given instant in UTC, one has to know the timezone that is being
> referred to. The answer could be Sunday, 31 December 2017 for one observer,
> and Monday, 1 January 2018 for another.
>
> So, contrary to your statement, I don’t see how I can know the date without
> also knowing the Time Zone.
>
> Andrew
>
