Time::Local is ancient and included in the Perl core:

#!/usr/bin/perl -w
use strict;
use Time::Local 'timegm';
my $stamp = '20150619-17:30:43.616';
my @nn = $stamp =~ /([.][0-9]+|[0-9]{2})/g;
my $f = pop @nn;        # Fractional seconds
my $cc = shift @nn;     # Century
my $yy = shift @nn;     # Year
$nn[0] -= 1;            # Make month 0-based (ugh)
unshift @nn, "$cc$yy";  # Put 4-digit year back in front.
$ENV{TZ} = "US/Eastern";
@nn = localtime( timegm( reverse @nn ) );
$nn[4]++;               # Make month 1-based (ugh)
$nn[5] += 1900;         # (ugh)
$stamp = sprintf "%d%02d%02d-%02d:%02d:%02d%s",
    @nn[reverse 0..5], $f;
print "$stamp\n";
__END__
20150619-13:30:43.616
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