title: perl subtract one month from date
body: <p>I get the dates in format %dd.%mm.%YYYY and I'm trying to substract one month, using Perl.</p>
  
  <p>examples: 12.07.2013 -> 12.06.2013 , 30.09.2013 -> 31.08.2013</p>
  
  <p>Should I use Date::Calc? Any ideas?</p>
  
  <p>Thanks</p>