my %reasons;
while (my($city, $code_info) = each %$switch_hash) {
	my ($code, $date_info) = %$code_info;
	while(my ($date, $reason) = each %$date_info) {
		next unless $reason =~ /^(\d+):(.*)/;
		$date_info->{$date} = $1;
		$reasons{"$city:$date"} = $2;
	}
}

##</code><code>##

my $switch_hash = {
	'Washington:uslecwas5e1' => {
		'01-AUG-2002' => ''
	},
	'Charleston:uslecchst5e1' => {
		'01-AUG-2002' => ''
	},
	'Richmond:uslecric5e1' => {
		'01-AUG-2002' => ''
	},
# ...

##</code><code>##

my $switch_hash = {
	'Washington' => {
		CODE => 'uslecwas5e1',
		'01-AUG-2002' => ''
	},
# ...

##</code><code>##

my %reasons;
while (my($city, $info) = each %$switch_hash) {
	while(my ($date, $reason) = each %$info) {
		next unless $reason =~ /^(\d+):(.*)/ and $date ne 'CODE';
		$info->{$date} = $1;
		$reasons{"$city:$date"} = $2;
	}
}