Thanks for your response, Stephen. Unfortunately, I'm still confused, as my test doesn't cross a DST boundary. Furthermore, the timezone of the box I ran the test on is GMT. So the DateMidnight and LocalDate should be effectively the same.
Forgetting DateMidnights, there's also a discrepency between methods 1 and 3. The FAQ "How do I calculate the difference between two dates?" suggests these should give the same result, in my opinion. Many thanks, Gareth -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Stephen Colebourne Sent: 06 January 2007 02:01 To: Discussion of the Joda project Subject: Re: [Joda-interest] daysBetween inconsistency Hi Gareth, When you convert to a DateMidnight, you add in a timezone - the defaault for your box. If your test crosses a DST boundary, then the length of a day may be 23 or 25 hours. Also, when converting to a DateMidnight, the date may not actually have a time at midnight (due to DST rules). All these factors combine to mean that the comparison differs for DateMidnight and LocalDate. The exception is if you setup the DateMidnight with the UTC timezone - then you will get the same result. Stephen [EMAIL PROTECTED] wrote: > I have been looking into joda time and am finding it considerably > easier to work with than Date, Calendar, etc. > > However, I have come across the following issue with the latest > release version. I've searched the mailing list but can't see any > mention of it. > > Is the following inconsistency a bug or a feature? > > Code: > LocalDate today = new LocalDate(); > LocalDate futureDay = today.plusDays(5); > > // Method 1: > Days days1 = Days.daysBetween(today,futureDay); > > // Method 2: > DateMidnight dmToday = today.toDateMidnight(); > DateMidnight dmFutureDay = futureDay.toDateMidnight(); > Days days2 = Days.daysBetween(dmToday,dmFutureDay); > > // Method 3: > Period period = new Period(today, futureDay); > > System.out.println("Method 1 = " + days1.getDays() + " days."); > System.out.println("Method 2 = " + days2.getDays() + " days."); > System.out.println("Method 3 = " + period.getDays() + " > days."); > > Output: > > Method 1 = 4 days. > Method 2 = 5 days. > Method 3 = 5 days. > > The first method is the most intuitive and the one I would like to > use, however when calculating the number of days from today until a > certain date, it gives the incorrect answer (I appreciate "days > between" is open to interpretation, although method 2 uses the same > method). 2 and 3 both give the desired result. > > Based on the following quote I would expect methods 1 and 2 to give > the same results: > >> ** Stephen Colebourne <[EMAIL PROTECTED]> wrote ** >> >> >> Replying quickly... >> >> A LocalDate and a DateMidnight in UTC ought to be effectively > identical, >> as they are internally. > > The same seems to happen for finding years between two dates as well > as days. > > Many thanks, > > Gareth > > > PLEASE READ: The information contained in this email is confidential > and intended for the named recipient(s) only. 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