print weeksToDays ( 1, 2013) ; (1st week of 2013) #### 31/12/2012 to 8/1/2012 (it should be ...to 6/1/2013) #### print weeksToDays ( 2, 2013) ; (2nd week of 2013) #### 7/1/2013 to 13/1/2013 #### use Date::Calc qw ( Monday_of_Week Add_Delta_Days ); sub weekToDays { $week = shift; $year = shift; ($year,$month,$day) = Monday_of_Week($week,$year); ($y, $m, $d) = Add_Delta_Days( Monday_of_Week( $week, $year ), 6); return "$day/$month/$year to $d/$m/$y"; } print "First week of 2013: ".weekToDays ( 1, 2013) ."\n" ; print "Second week of 2013: ".weekToDays ( 2, 2013) ."\n" ;