bug#7223: DATE 8.5 and back -- Invalid date with specific dates

[Bob Proulx]

Lucien Raven wrote:
> This problem was reproduced in several versions of 'date', and the
> oldest one I could reproduce the problem was 6.10.
> 
> But it doesn´t happen in older ones (tried on 'date' 5.97)

Thank you for the report.  But the critical piece of information you
didn't list was what timezone you are trying to use.  That is an
essential piece of information to know to understand your problem.  It
is very likely that the invalid dates you list did not exist in your
timezone.

> PS: The dates correspond to the third Sunday of October.

Is that when Daylight Savings Time changes?  If the time did not exist
because DST changes caused that time to be skipped over then that
point in time will not exist and it will be reported as an invalid
date.  To avoid those issues you might try using UTC.  Or you might
try using noon time instead since it would be unusual for DST to
change around noon.

  $ date +%Y%m%d --date='2010-10-17 12:00'
  20101017

Here is a reference with more details.

  
http://www.gnu.org/software/coreutils/faq/#The-date-command-is-not-working-right_002e

Bob