The module is working as advertised. There's this concept out there of performing mathematical operations on non-anchored date fragments which is not really that useful in the real world, presuming you want accurate answers.

When dealing with absolute dates (meaning YMDHMS, rather than non-anchored date fragments) you are better off converting both dates into seconds-since-epoch, computing the delta, then applying this delta (in seconds) to any target dates of interest. (all math happens in the world of seconds).

This is still fraught with potential errors, however, including DST issues and leap-seconds.

Check out the collection of nodes in the Q&A section QandASection: dates and times.

I'd also suggest looking into the Perl DateTime Suite if you're interested in detailed, and correct, date calculations.

Matt

In reply to Re: Unexplained Behavior in Date::Calc by mojotoad
in thread Unexplained Behavior in Date::Calc by jpfarmer

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