Look at Time::HiRes module for milliseconds.

1. Normalize your times before you start calculating.
2. Check the Time::... modules on CPAN, via PPM or your distro's packages

You're dealing with part one at least in part. Good. We admire self-help.

Time::HiRes (subject of two previous replies) is widely cited here at PM for part two. Perhaps you should also familiarize yourself with the use of Google site:PerlMonks ..., Search and Super Search.

Time::HiRes is not really helping me. I checked the CPAN for time packages many hours and found nothing.

Believe me I am using google, super search and cpan a lot before asking here. And I really want to learn from you and not that you provide me a full solution.

My goal was it to use a common module. But because I do not find one, I've written my own class.

Here you can see the code.

EDIT: Updated code and rewrote some paragraphs which described the code.

EDIT: Now I found a package which has milli and nanoseconds and has math and duration stuff: DateTime. I'll look deeper into it. Perhaps I can replace my own class by using this module. But it was cool to try overloading and writing an own module.

package My::TimeCalc;

use strict;

use overload ('""' => 'asString',
              '+'  => 'add',
              '-'  => 'subtract',
              '*'  => 'mult',
              '/'  => 'divide',
              '<=>' => 'compare');

sub new
{
    my ($class, $time_str) = @_;
    my $seconds;
    my $self = \$seconds;
    bless($self, $class);

    $time_str = defined($time_str) ? $time_str : "0";
    return( $self->fromString($time_str) );
}

sub sec
{
    my ($self) = @_;
    return $$self;
}

sub asString
{
    my ($self, $precision) = @_;

    $precision = defined($precision)?$precision:2;

    my $min = int(abs($$self) / 60.0);
    my $sec = abs($$self) % 60.0;
    my $frac = sprintf("%.${precision}f", abs($$self - int($$self))) *
+ 10**$precision;

    my $time_str = "";
    if( $$self < 0 ) { $time_str = "-"; }
    $time_str .= "$min:" if( $min != 0 );
    $time_str .= sprintf("%02d", $sec) if ( ($min != 0) || ($sec != 0)
+ );
    $time_str .= "," . sprintf("%0${precision}d", $frac) if ( $frac !=
+ 0 );

    if( ($min == 0) && ($sec == 0) && ($frac == 0) ) { $time_str = "0"
+; }

    return( $time_str );
}

sub fromString
{
    my ($self, $time_str) = @_;

    # 1) min:sec,frac  e.g. "5:29,11"
    # 2) sec,frac       e.g. "29,11"
    # 3) sec           e.g. "29"
    # 4) ,frac           e.g. ",11"
    # 5) min:sec       e.g. "5:29"
    # Note: instead of "," you can also take "."!

    # remove leading and trailing whitespace characters
    $time_str =~ s/^\s+|\s+$//g;

    # valid time string
    if( ($time_str =~ m/^(?<min>\d+):(?<sec>\d+)(,|\.)(?<frac>\d+)$/) 
+||
        ($time_str =~ m/^(?<sec>\d+)(,|\.)(?<frac>\d+)$/) ||
        ($time_str =~ m/^(?<sec>\d+)$/) ||
        ($time_str =~ m/^(,|\.)(?<frac>\d+)$/) ||
        ($time_str =~ m/^(?<min>\d+):(?<sec>\d+)$/) )

    {
        no warnings 'uninitialized'; # intention: undef treated as zer
+o
        $$self = ($+{'min'} * 60.0) + $+{'sec'} + ($+{'frac'}/(10**len
+gth($+{'frac'})));
        return( $self );
    }

    return( undef );
}

sub add
{
    my ($self, $another) = @_;

    my $result;

    if( ref($another) eq "My::TimeCalc" )
    {
        $result = $self->sec() + $another->sec();
    }
    else
    {
        $result = $self->sec() + $another;
    }

    return( new My::TimeCalc($result) );
}

sub subtract
{
    my ($self, $another) = @_;

    my $result;

    if( ref($another) eq "My::TimeCalc" )
    {
        $result = $self->sec() - $another->sec();
    }
    else
    {
        $result = $self->sec() - $another;
    }

    return( new My::TimeCalc($result) );
}

sub mult
{
    my ($self, $another) = @_;

    my $result;

    if( ref($another) eq "My::TimeCalc" )
    {
        $result = $self->sec() * $another->sec();
    }
    else
    {
        $result = $self->sec() * $another;
    }

    return( new My::TimeCalc($result) );
}

sub divide
{
    my ($self, $another) = @_;

    my $result;

    if( ref($another) eq "My::TimeCalc" )
    {
        $result = $self->sec() / $another->sec();
    }
    else
    {
        $result = $self->sec() / $another;
    }

    return( new My::TimeCalc($result) );
}

sub compare
{
    my ($self, $another) = @_;

    if( ref($another) eq "My::TimeCalc" )
    {
        return( $self->sec() <=> $another->sec() );
    }
    else
    {
        return( $self->sec() <=> $another );
    }
}

1;
[download]

And now I come back to the example ($t1 * 4) + $t2.

use strict;
use warnings;

use My::TimeCalc;

my $t1 = new My::TimeCalc("16:51,12");
my $t2 = new My::TimeCalc("34:48,14");
my $t = ($t1 * 4) + $t2;

print($t,"\n"); # 102:12,62
[download]

It's the first time I used perl in an object oriented way and my first test with this new class were successful.

I'm sure that it is not good code. I want to change the parse and print function to common time formats. Perhaps here I can use an official module.

Would be great if you can give me feedback. What could I do better?

Thank you

Dirk