!/usr/bin/perl -w
use strict;

my $switch_hash = {
 'Washington'     =>{uslecwas5e1  =>{'01-AUG-2002' => '' }},
 'Charleston'     =>{uslecchst5e1 =>{'01-AUG-2002' => '' }},
 'Richmond'       =>{uslecric5e1  =>{'01-AUG-2002' => '' }},
 'West Palm Beach'=>{uslecwpb5e1  =>{'01-AUG-2002' => '' }},
 'Atlanta'        =>{uslecatl5e1  =>{'14-AUG-2002' => '10:reason',
                                     '15-AUG-2002' => '11:new reason' }},
 'Fort Myers'     =>{uslecftm5e1  =>{'01-AUG-2002' => '' }},
 'Mobile'         =>{uslecmob5e1  =>{'01-AUG-2002' => '' }},
 'Nashville'      =>{uslecnas5e1  =>{'01-AUG-2002' => '' }},
 'Orlando'        =>{uslecorl5e1  =>{'12-AUG-2002' => '2:different reason' }},
 'Charlotte'      =>{uslechar5e1  =>{'01-AUG-2002' => '' }},
 'Louisville'     =>{usleclou5e1  =>{'01-AUG-2002' => '' }},
 'Memphis'        =>{uslecmem5e1  =>{'01-AUG-2002' => '' }},
 'Philadelphia'   =>{uslecphi5e1  =>{'01-AUG-2002' => '' }},
 'Chattanooga'    =>{uslecchat5e1 =>{'01-AUG-2002' => '' }},
 'Birmingham'     =>{uslecbir5e1  =>{'01-AUG-2002' => '23:junk' }},
 'Greensboro'     =>{uslcgb5e2sm  =>{'01-AUG-2002' => '' }},
 'New Orleans'    =>{uslecnew5e1  =>{'01-AUG-2002' => '22:fake' }},
 'Jacksonville'   =>{uslecjac5e1  =>{'01-AUG-2002' => '' }},
 'Norfolk'        =>{uslecnor5e1  =>{'01-AUG-2002' => '' }},
 'DEX'            =>{chrdex       =>{'13-AUG-2002' => '1:some stuff',
                                     '19-AUG-2002' => '1:reason again' }},
 'Atlanta II'     =>{uslecat25e1  =>{'01-AUG-2002' => '' }},
 'Baltimore'      =>{uslecbal5e1  =>{'01-AUG-2002' => '' }},
 'Raleigh'        =>{uslecral5e1  =>{'01-AUG-2002' => '' }},
 'Pittsburgh'     =>{uslecpit5e1  =>{'01-AUG-2002' => '' }},
 'Miami'          =>{uslecmia5e1  =>{'01-AUG-2002' => '' }},
 'Knoxville'      =>{uslecknxv5e  =>{'01-AUG-2002' => '' }},
 'Tampa'          =>{uslectam5e1  =>{'01-AUG-2002' => '' }},
}; 

my %reasons;
while (     my ($city, $v1) = each %$switch_hash ){
  while (   my ($usl,  $v2) = each %$v1          ){
    while ( my ($date, $v3) = each %$v2          ){
      next unless $v3;
      my ($hours, $reason) = split ':', $v3, 2;
      warn if exists $reasons{"$city:$date"};
      $reasons{"$city:$date"} = $reason;
#     push @reasons, [$city, $date, $reason ];
      $v2->{$date} = $hours; # Can't use $v3 here; it is a copy!
    }
  }
}

use Data::Dumper;
$Data::Dumper::Useqq = 1;
print Data::Dumper->Dump(
  [   \%reasons, $switch_hash  ],
  [qw( *reasons   switch_hash )]
);