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

sub timestamp {
    # return current timestamp in HHMMSS format
    my ($second, $minute, $hour) = (localtime)[0,1,2];
    sprintf ("%02d%02d%02d", $hour, $minute, $second);
}

sub datestamp {
    # return current date in DDMMCCYY format
    my ($day, $month, $year) = (localtime)[3,4,5];
    sprintf ("%02d%02d%04d", $day, $month + 1, $year + 1900);
}
my $filename = 'new.file.d{activity_date}.t{activity_time}';

$filename =~ s/{activity_date}/datestamp/e;
$filename =~ s/{activity_time}/timestamp/e;

print $filename;
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Converts a time as returned by the time function to a 9-element array
with the time analyzed for the local time zone.  Typically used as
follows:

    #  0    1    2     3     4    5     6     7     8
    ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
                                                localtime(time);

my @now = localtime();
$now[4]++; $now[5] += 1900;
$_ < 10 and $_ = "0$_" for @now[0..4];

my $ddmmyyyy = $now[3] . $now[4] . $now[5];
my $hhmmss   = $now[2] . $now[1] . $now[0];
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2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$
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Robin Barker