[rules-users] AGE problem

[Greg Barton]

I was about to suggest this. :)  And one advantage of using joda time is that version 1.6 is already included as a dependency of drools.

--- On Tue, 2/23/10, Jason Smith <jsmith at infotrustgroup.com> wrote:

> From: Jason Smith <jsmith at infotrustgroup.com>
> Subject: Re: [rules-users] AGE problem
> To: "Rules Users List" <rules-users at lists.jboss.org>
> Date: Tuesday, February 23, 2010, 7:45 AM
> Hey, I haven't been following this
> thread, but you can use Joda Time to get much better, easier
> results.  For instance, you can add 1 month to a
> DateTime by using a new Period("P1M") [that is, a period of
> 1 month] - all done according to ISO8601 standards, so it
> works flawlessly, including adjustments for things like
> daylight savings time (so you don't have to think about it
> much).
> 
> In business, we live and die by precise time
> calculations.  Think of it as being like a check
> writing program that "estimates" a salary, and then pays the
> employee that amount.  Get your torches and
> pitchforks!
> 
> Jason Smith
> ________________________________________
> From: rules-users-bounces at lists.jboss.org
> [rules-users-bounces at lists.jboss.org]
> On Behalf Of Pavel Tavoda [pavel.tavoda at gmail.com]
> Sent: Tuesday, February 23, 2010 1:30 AM
> To: Rules Users List
> Subject: Re: [rules-users] AGE problem
> 
> Try to do this in bank application. People come 1 hour
> after they date
> expired and try to charge them for sooner withdrawal
> because you
> calculate with 365.25 not 365 days. You will be kicked,
> believe me.
> 
> Pavel
> 
> 
> 2010/2/23 Wolfgang Laun <wolfgang.laun at gmail.com>:
> > On Tue, Feb 23, 2010 at 8:07 AM, djb <dbrownell83 at hotmail.com>
> wrote:
> >>
> >> I think though that the majority of uses for a
> rules engine is in a
> >> business
> >> context, where they don't use astronomical time.
> >>
> >> If the doctor's orders are:
> >> "You cannot get out of bed for 2 months"
> >>
> >> This means 59 days if he told you February 1st,
> and it means 62 days if he
> >> told you July 1st.
> >>
> >
> > This is a particularly bad example, because doctors
> can't say that - at
> > least not one I'd trust ;-)
> >
> > I'm arguing that you cannot expect a computer program
> to relieve you from
> > the burden of defining what you mean by a "duration of
> one year" (or month).
> > Some legal rules require a person to have a certain
> age, and it is (for
> > humans)
> > more convenient to decide this on a person's birthday
> YMD plus an increment
> > in the Y number. If  your application requires
> you to use an increment in
> > the year
> > component of the YMDhms representation of a point in
> time, then you are
> > indeed stuck with Calendar and the resulting overhead.
> (Memoizing
> > the results of YMDhms +/- n years might speed things
> up, for the usual
> > price.)
> >
> > But many applications would be satisfied with using a
> fixed duration for
> > a year in terms of 365 or 365.25 or some such value.
> If, for instance, you
> > have a  library, and you must decide to move a
> book into deep storage
> > "if it has  not been requested for more than a
> year" you might calculate
> > this (faster) by adding 356*24*60*60 to the clock
> value of the last return.
> >
> > -W
> >
> >> So at least for me, I am going to have to work out
> a plan that involves
> >> GregorianCalendar.
> >>
> >> --
> >> View this message in context:
> >> http://n3.nabble.com/AGE-problem-tp215215p354847.html
> >> Sent from the Drools - User mailing list archive
> at Nabble.com.
> >> _______________________________________________
> >> rules-users mailing list
> >> rules-users at lists.jboss.org
> >> https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
> > _______________________________________________
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> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
> 
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