When examining your data you should probably examine what you want, in this cae 2 arrays keyed on the first column, there's no need to create sepearate data structures and in fact having a single data structure makes passing it to subsequent functions easier. So here's a solution using a single data structure with each customer referencing 2 arrays, one for time and the other for location. 
~/$ cat tmp.pl
#!/usr/bin/perl
use strict;
use warnings;

open(my $customers, $ARGV[0])|| die "Couldn't open $ARGV[0] $!\n";
my %cust;
while(<$customers>){
    chomp;
    my @rec=split(/\s+/, $_);
    push @{$cust{$rec[1]}->{time}},$rec[0];
    push @{$cust{$rec[1]}->{location}},$rec[2];
}

for my $cust (sort keys %cust){
    print "$cust: ",join(" ",@{$cust{$cust}->{time}})," : ",join(" ",@
+{$cust{$cust}->{location}}),"\n";
}
~/$ perl tmp.pl tmp.dat 
a: 12:10 12:13 : america australia
b: 12:11 2:30 : bombay bhutan
c: 12:12 : calcutta
n: 3:40 : neterland

[download]
print "Good ",qw(night morning afternoon evening)[(localtime)[2]/6]," fellow monks."

In reply to Re: how to iterate over multiple hashes with same key value by Utilitarian
in thread Reaped: how to iterate over multiple hashes with same key value by NodeReaper

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.