Chris, makeUTC already solved your both problems right?
- it makes Date comparable, even when coming from DateAndTime of
different time zone
- it makes hash fast enough

In this case I don't see the point of creating yet another class, or
do I miss something ?

And weather makeUTC should be the default or not, I don't really care,
but if you make it the default, at least make a copy of the
DateAndTime, otherwise DateAndTime>>asDate will modify the receiver.

Nicolas

2012/2/3 Casey Ransberger <casey.obrien.r at gmail.com>:
> Top post: What he said. Or maybe we move the timezone specific stuff down a notch in the hierarchy, and have a class above it that just does fast UTC, but please don't take it out. It's one of those wonderful things most systems don't have.
>
> +1 for Dave's argument. Besides, I can't get a date to save my life!
>
> On Feb 2, 2012, at 1:01 PM, "David T. Lewis" <lewis at mail.msen.com> wrote:
>
>> On Thu, Feb 02, 2012 at 02:50:56PM -0500, Yanni Chiu wrote:
>>> On 02/02/12 11:25 AM, Chris Muller wrote:
>>>>
>>>> Best to strip all Dates (NOT DateAndTimes) of their timezone.
>>>
>>> IMHO, there are two different concepts getting mixed up.
>>
>> Correct.
>>
>>>
>>> 1) There is a "date", which has a day, month and year (and calendar). If
>>> you're modeling dates to be printed on a 12-month calendar that can be
>>> used anywhere in the world, then this is the kind of date you want.
>>>
>>
>> Yes, I think that was more or less the original implementation in earlier
>> Squeak before Chronology was added.
>>
>>
>>> 2) There is the 24hr period (sometimes 23hr or 25hr) which corresponds
>>> to that "date". This 24hr period is timezone dependent. If you're making
>>> a scheduling application, then this is the kind of date you need.
>>
>> Yes, and this is the meaning of "date" in more recent Squeak.
>>
>>>
>>> So, i agree: remove timezone from Date.
>>
>> Date does not have a timezone. It has a start DateAndTime, which in
>> turn has an offset from UTC. Neither Date nor DateAndTime has a timezone.
>>
>>>
>>>> I propose Date's, by default, be created with the UTC offset, NOT the
>>>> local offset.
>>>
>>> Disagree. The natural default for today, is the date in my local
>>> timezone. Maybe #todayUTC should be introduced. Then why not add
>>> #todayInTimezone: too. Hmm...timezones seem to be creeping back in.
>>>
>>
>> +1
>>
>> And more generally, don't change it at all unless we can clearly
>> state the (new?) meaning of "date" and write it down in a class
>> comment for all to see and understand. A "date" may mean very
>> different things in the context of different use cases, so if
>> there is an interest in making something with a different meaning,
>> it suggests that a different class should be invented. There is
>> also an ANSI Smalltalk definition to keep in mind here.
>>
>> Dave
>>
>> p.s. I just ran the unit tests for TimeZoneDatabase and see new
>> failures, but only when running on the standard interpreter. Did
>> we change something in the image in a Cog-dependent way? I'll track
>> it down as soon as I get some time but if someone can point me to
>> the answer I'd appreciate it.
>>
>>
>