my $currentperiod = 'P08';
print "\nCurrent Period is (LE period is current period incremented by one): ". $currentperiod;
my $LEperiod = 'xxxxx';

my %hash = (
   P01 => 'P02',
   P02 => 'P03',
   P03 => 'P04',
   P04 => 'P05',
   P05 => 'P06',
   P06 => 'P07',
   P07 => 'P08',
   P08 => 'P09',
   P09 => 'P10',
   P10 => 'P11',
   P11 => 'P12',
   P12 => 'P01',
);

if( exists $hash{ $currentperiod } ){
   $LEperiod = $hash{$currentperiod};
}

print "\nCurrent Period after ifs is: ". $currentperiod;
print "\nDefault LE period is : " . $LEperiod . "\n\n";