in reply to Re^2: time difference calculation
in thread time difference calculation

You have a difference of 750 hours. Have you looked at the expected time difference?

Maybe you want to study again the exact ranges of allowed input parameters for Time::Local. Especially re-read the second paragraph of the description, where the documentation draws particular attention to the allowed values for the month.

Maybe you want to try the following dates and study the error message you get

2013-02-31 2013-01-28 2013-01-29 2013-01-30 2013-01-31