On 6/3/05, Rick Measham <[EMAIL PROTECTED]> wrote:
> Matthew Persico wrote:
> > 1) Add a convenience method called 'today' to DateTime, which is the
> > same as Date::Time->now->trunc(to=>day)
>
> Already there ..
> $today = DateTime->today();
Hmm, don't know how I missed that one...
>
> > 2) All business dates will have no time component. All decrements and
> > increments of business dates will be a number of days - I don't think
> > there is a concept of business weeks or months...
>
> Absolutely disagree on this point. You have to have finer control than
> days. If a project is going to take 100 man-hours and you have 7 people
> working on it, you need to be able to do:
When I say business date in the US, I'm thinking in terms of dates on
which financial transactions are able to be executed or settled. Time
is irrelevant: for example, if the trade executes on a Friday, it
cannot settle on Sat or Sun because the are not business days. Hours
are irrelevant.
If I were writing an object to handle your examples below, I'd call it
DateTime::Calendar::Man (as in man-hours, man-days, man-weeks, etc,
with apologies to the other half of the human race...)
which would need a holiday calendar attached to it in some way (much
as my DateTime::Business would) to get the math right.
Between your comments and those of [EMAIL PROTECTED] prior to yours, I
am starting to think that the only "right" way to do this is to create
the calendar as a separate entity and feed it to DateTime instead of
trying to create Yet Another Sub Class of DateTime. The only thing I
have to account for in my world is setting time to 00:00
[snip]
> Also, you cannnot ignore things like weeks and months. Especially
> months. From a business POV, in Australia note the following behaviour
> would be 'correct':
>
> $this_year = DateTime::Calendar::Business::Australia->now->trunc( to =>
> year );
>
> print $this_year->datetime;
>
> # 2004-07-01T00:00:00
>
> In Australia, the tax year start on July 1st and finishes on June 30th
> and so truncating to year would have to return a July 1st date. In the
> states I believe it's April 19th or some such.
In the US, April 15 is the date by which you have to file your tax
return for the previous year. The tax year is Jan 1 through Dec. 31
for all personal taxes. I don't know the effect on taxes for a
business with a fiscal year != physical year. Most file quarterly
anyway - the end of year may only affect when any refunds are actually
refunded to a business.
> There's probably hundreds, if not thousands, of different ways of
> defining business days and so I'd suggest implementing a simple way to
> localize and cascade your data such as this:
>
> package DateTime::Calendar::Business::Australia;
>
> @ISA = qw/DateTime::Calendar::Business/;
>
> $YEARSTART = { month => 7, day => 1 };
>
> @BUSINESSHOURS = [
> 1 => [ {hour => 9}, {hour => 17} ],
> 2 => [ {hour => 9}, {hour => 17} ],
> 3 => [ {hour => 9}, {hour => 17} ],
> 4 => [ {hour => 9}, {hour => 17} ],
> 5 => [ {hour => 9}, {hour => 17, minute => 30} ],
> 6 => [ {hour => 9}, {hour => 12} ],
> 7 => [ ],
> ];
>
> @PUBLICHOLIDAYS = [
> { month=>1, day=>26 }, #Australia Day
> { month=>4, day=>25 }, #ANZAC Day
> { month=>12, day=>25 }, #Christmas Day
> { DateTime::Event::Easter->new( day=> -2) }, #Good Friday
> { DateTime::Event::Easter->new( day=> 0) }, #Easter Sunday
> ];
>
> package DateTime::Calendar::Business::MyCompany;
>
> @ISA = qw/DateTime::Calendar::Business::Australia/;
>
> @BUSINESSHOURS = [
> 1 => [ {hour => 9}, {hour => 17, minute => 30} ],
> 2 => [ {hour => 9}, {hour => 17, minute => 30} ],
> 3 => [ {hour => 9}, {hour => 17, minute => 30} ],
> 4 => [ {hour => 9}, {hour => 21} ],
> 5 => [ {hour => 9}, {hour => 21} ],
> 6 => [ {hour => 9}, {hour => 17} ],
> 7 => [ {hour =>10}, {hour => 16} ],
> ];
>
>
> __END__
>
> Once you have all your definitions in place, then a
> DateTime::Calendar::Business object should work just like a DateTime
> object -- you should be able to truncate it, add to it, subtract from it
> etc. Just have to remember that a day on your calendar is not the same
> as a day on the gregorian calendar, your days are only 7 or 8 hours each
> and you weeks are 5 or 6 days long.
>
> Cheers!
> Rick Measham
>
>
Aside from the use of hours, which I don't need,
--
Matthew O. Persico
