#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

sub print_timestamp {
    local *_get_formatted_time = sub {
        return $_[0] . uc scalar localtime;
    };
    return _get_formatted_time(@_);
}

say print_timestamp('The time was: ');

__END__

$ perl test.pl
The time was: FRI AUG 25 15:18:08 2017