my %timer = (
    check_conn => 0,
    check_rev  => 0,
};
my %interval = (
    check_conn => 5,  # check conn every 5 min
    check_rev  => 55, # and revocation at 55min
};

while (1) {
    my $now = time;
    if ($now + interval{check_conn} * 60 > $timmer{check_conn} ) { #passed mark
        $timer{check_conn} = $now + interval{check_conn} * 60;
        # signal conn thread to do its work
        $conn_q->enqueue("Get on with it"); 
    }
    # similar for check rev list
    #
    sleep 10; # or 60, or 300...
}