Bug in datetime arithmetic when subtracting hours? about datetime-fortran HOT 3 CLOSED

Hi Chris, thanks for submitting this issue. I just noticed this now, I should probably turn on e-mail notifications. Will look into it and let you know what I find. Thanks.

from datetime-fortran.

Hi Chris, I was able to reproduce your bug. Note that the time change was also incorrect for December, indicating that datetime+timedelta(hours=-6) was misbehaving whenever daysInMonth(datetime%month - 1,datetime%year) < 31. The bug is fixed by changing the subroutine addDays from this:

    ELSEIF(self%day < 1)THEN
      self%day = self%day+daysInCurrentMonth
      self%month = self%month-1

to:

    ELSEIF(self%day < 1)THEN
      self%month = self%month-1
      self%day = self%day+daysInMonth(self%month,self%year)

The problem was occuring because switching into a previous month caused the day component to update using an old value of daysInCurrentMonth.

The output of your program is now:

 2013-01-01T00:00:00.000 -6hrs = 2012-11-30T18:00:00.000
 2013-02-01T00:00:00.000 -6hrs = 2013-01-31T18:00:00.000
 2013-03-01T00:00:00.000 -6hrs = 2013-02-28T18:00:00.000
 2013-04-01T00:00:00.000 -6hrs = 2013-03-31T18:00:00.000
 2013-05-01T00:00:00.000 -6hrs = 2013-04-30T18:00:00.000
 2013-06-01T00:00:00.000 -6hrs = 2013-05-31T18:00:00.000
 2013-07-01T00:00:00.000 -6hrs = 2013-06-30T18:00:00.000
 2013-08-01T00:00:00.000 -6hrs = 2013-07-31T18:00:00.000
 2013-09-01T00:00:00.000 -6hrs = 2013-08-31T18:00:00.000
 2013-10-01T00:00:00.000 -6hrs = 2013-09-30T18:00:00.000
 2013-11-01T00:00:00.000 -6hrs = 2013-10-31T18:00:00.000
 2013-12-01T00:00:00.000 -6hrs = 2013-11-30T18:00:00.000

This fix has been commited to the master repo.

Thank you for improving datetime-fortran.

from datetime-fortran.

Thanks for fixing this, Milan.
It's a really useful library!
All the best,
Chris.

On 5 February 2014 18:48, Milan Curcic [email protected] wrote:

Closed #6 #6.

Reply to this email directly or view it on GitHubhttps://github.com//issues/6
.

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