UPDATE</b: Upon further inspection the premise of my roll-your-own is similar to what you are doing, I approve ;-). However I believe the suggestion meets your requirement of simplifying the process, YMMV.

--
perl -pe "s/\b;([st])/'\1/mg"

$date = date(<PUT YOUR FORMAT HERE>) # create new date object
$seonds = $num_secs . "s";
$date += $seconds
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I think it should be that simple. Sorry I am being so vague here, but the Class::Date docs are pretty good and will no doubt enlighten you better than I have.

Caveat:

Unless you're using GMT, or are working within a time zone that does not honor daylight savings time, doing simple math on raw time components will give you the wrong results during two one-hour windows each year.

Since the daylight savings switch happens at 1-2am, this might not be an issue to you. But do be aware.

Using one of the various Data/Time packages is safer.

use strict;

use Date::Calc;
my ($year,$month,$day, $hour,$min,$sec) = Date::Calc::Today_and_Now();

my $addDays=0;
my $addHours=0;
my $addMins=0;
my $addSecs=10;

my ($nyear,$nmonth,$nday,$nhour,$nmin,$nsec) =
  Date::Calc::Add_Delta_DHMS($year,$month,$day, $hour,$min,$sec,
  $addDays,$addHours,$addMins,$addSecs);

print "Now          : $month/$day/$year $hour:$min:$sec \n";
print "Now + 10 secs: $nmonth/$nday/$nyear $nhour:$nmin:$nsec \n";
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my $current_time="00:02:25";
my $time_inc = 10;
my ($h, $m, $s) = split(/:/, $current_time);

$s += $time_inc;  ### 1 ###

$m += int($s / 60);  ### 2 ###
$s %= 60;  ### 3 ###

$h += int($m / 60);
$m %= 60;

my $new_time = join ':', $h, $m, $s;

print "$new_time\n";
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What we do is increase the seconds without caring about the overflow at first (see 1.) - the result may well go over 60. Then we increase the minutes by the nonfractional part of seconds / 60 (see 2.) and set the seconds to the remainder of seconds / 60 (see 3.). Since the minutes may have gone over 60 we repeat the same process there, adding the overflow to the hours. Finally we join the values with double colons and print the result.

Update: My bad. Listen to belg4mit. I would suggest a look at Time::Local instead though - since that comes bundled with Perl.

Makeshifts last the longest.

#!/usr/bin/perl -wT
use strict;
use Time::Piece;

my $time    = "10:30:05";
my $delta   = 1000;
my $newtime = deltatime($time,$delta);

print "$time + $delta => $newtime\n";

sub deltatime {
  my $t = Time::Piece->strptime(shift,"%T") + shift;
  return $t->strftime("%T");
}
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perl -MTime::Piece -le'print+(Time::Piece->strptime(pop,"%T")+pop)->st
+rftime("%T")' 1000 10:30:05
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-Blake

#!/usr/bin/perl
$now = '00:00:00';
for (0..60*60*24+5) {
    print adjust_time($now, $_), "\n";
}
exit;

sub adjust_time {
    my $start_time = shift;
    my $increment = shift;

    my ($hour, $min, $sec) = split /:/, $start_time;
    my $seconds = 3600 * $hour + 60 * $min + $sec;
    $seconds += $increment;

    $hour = sprintf "%02d", ($seconds/3600) % 12; # add + 1 here for 1
+2 hour format;
    $min = sprintf "%02d", ($seconds/60) % 60;
    $sec = sprintf "%02d", $seconds % 60;
    return "$hour:$min:$sec";
}
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my $secs = 60;
my $time = '23:59:25';

my @time = split /:/, $time, 3;
$time[2] += $secs;

for (my $i = 2; $i >= 1; $i--) {
    if ($time[$i] >= 60) {
         $time[$i] -= 60;
         $time[$i-1]++;
    }
}

$time[0] -= 24 if $time[0] >= 24;
$time = join ':', map { length($_) < 2 ? "0$_" : $_ } @time;
print $time;
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gav^