PERL sorting CSV data

This script allow us to sort CSV data by column.

The objective is to sort data by date:
The script as below:

The input file data are in CSV format:

Build_Results,Build_Type,Duration_in_Minutes,Date,Hour,Weekday
Failed,,42,01/05/2007,08,Tuesday
Failed,,20,01/02/2007,10,Tuesday
......
Failed,,22,01/03/2007,07,Wednesday