Perl function to return a human readable string for a time duration in seconds.

my $str = human_time_diff(320);  # "5 minutes"
my $str = human_time_diff(3700); # "1 hour"

sub human_time_diff {
    my $seconds = int(shift());
    my $num     = 0;
    my $unit    = "";
    my $ret     = "";

    if ($seconds < 120) {
        $ret = "just now";
    } elsif ($seconds < 3600) {
        $num  = int($seconds / 60);
        $unit = "minute";
    } elsif ($seconds < 86400) {
        $num  = int($seconds / 3600);
        $unit = "hour";
    } elsif ($seconds < 86400 * 30) {
        $num  = int($seconds / 86400);
        $unit = "day";
    } elsif ($seconds < (86400 * 365)) {
        $num  = int($seconds / (86400 * 30));
        $unit = "month";
    } else {
        $num  = int($seconds / (86400 * 365));
        $unit = "year";
    }

    if ($num > 1) { $unit .= "s"; }
    if ($unit) { $ret = "$num $unit"; }

    return $ret;
}

See also: PHP version