This is kind of like Formatting elapsed time, but has more options and has date units from seconds into years.

sub dhm {
    my $time = shift;
    my (@times, @time);
    my @format = qw(m h d);

    push @times, ($time / 60) % 60;             # Minutes
    push @times, ($time / (60 * 60)) % 24;      # Hours
    push @times, int($time / (24 * 60 * 60));   # Days

    for my $i (0 .. $#times) {
    push @time, "$times[$i]\cB$format[$i]\cB" if $times[$i] > 0;
    }

    return join ' ', reverse @time;
}


sub time2string {
    my %defaults = (
        long_format => 1,
        spacing     => 1,
        bold        => 0
    );

    my $time = shift;
    my %args = (%defaults, @_);
    my @format;

    if ($args{format}) {
    $args{long_format} = 1;
    @format = split ' ', $args{format};
    }

    if (@format) {
    die "error: format needs excatly 7 values.\n" unless $#format == 6
+;

    } else {

    if ($args{long_format} == 1) {
        @format = qw(sec min hour day week month year);

    } elsif ($args{long_format} == 2) {
        @format = qw(second minute hour day week month year);

    } elsif (!$args{format} && !$args{long_format}) {
        @format = qw(s m h d w mo y);

    }
    }

    die "error: time must only only be digits.\n" if !defined $time ||
+ $time !~ /^\-?\d+$/;

    my $prefix = '';
    if ($time < 0) {
    $time = - $time;
    $prefix = "- ";
    }

    my (@times, @data);
    push @times, $time % 60;                    # Seconds
    push @times, ($time / 60) % 60;             # Minutes
    push @times, ($time / (60 * 60)) % 24;      # Hours
    push @times, int($time / (24 * 60 * 60));   # Days
 
    my $modulo = sub {
        my ($days, $d) = @_;
        my $return;
        if ($d >= $days) {
            $return = int($d / $days);
            $d = $d % $days;
        } else {
            $return = 0;
        }

        return $return, $d;
    };


    ($times[6], $times[3]) = $modulo->(365, $times[3]); # Years
    ($times[5], $times[3]) = $modulo->(30, $times[3]);  # Months
    ($times[4], $times[3]) = $modulo->(7, $times[3]);   # Weeks


    $time = defined $prefix ? $prefix : undef;

    for my $i (reverse 0 .. $#times) {
        next if $times[$i] == 0;

        $format[$i] .= $times[$i] > 1 && $args{long_format} && !$args{
+format} ? 's ' : ' ';
        $time       .= $args{spacing} ? "$times[$i] $format[$i]" : "$t
+imes[$i]$format[$i]";
    }

    $time =~ s#([A-Z]+)#\cB$1\cB#ig if $args{bold} == 1;

    return $time;
}
[download]

example usage:

  time2string(time, bold => 1) # Bold text for IRC.
[download]

9y 4mo 1w 2d 8h 13m 11s

  time2string(time, long_format => 1) # Use long(er) unit names.
[download]

9 years 4 months 1 week 2 days 8 hours 13 mins 11 secs

  time2string(time, long_format => 2) # Full length unit names.
[download]

9 years 4 months 1 week 2 days 8 hours 13 minutes 11 seconds

 time2string(time, format => 'Sec Min Hour Day Week Month Year'); # De
+fine your own unit names.
[download]

9 Year 4 Month 1 Week 2 Day 8 Hour 13 Min 11 Sec

  time2string(time, spacing => 0, format => 'Sec Min Hour Day Week Mon
+th Year'); # Turn off spacing.
[download]

9Year 4Month 1Week 2Day 8Hour 13Min 11Sec

  dhm(time) # For things that don't need a lot of spiff.
[download]

391d 17h 49m