private static function _pushTime($cmd)
        {
            // capture the time as early in the function as possible
            $mt = microtime();

            // set current running state depending on the command
            if ($cmd == static::CMD_START) {
                // check if the timer has already been started
                if (static::$_running === true) {
                    // ThinLog('Timer has already been started');
                    return;
                }

                // set current state
                static::$_running = true;

            } else if ($cmd == static::CMD_STOP) {
                // check if the timer is already stopped
                if (static::$_running === false) {
                    // ThinLog('Timer has already been stopped/paused or has not yet been started');
                    return;
                }

                // set current state
                static::$_running = false;

            } else {
                // fail execution of the script
                // ThinLog('Invalid command specified');
                return;
            }

            // recapture the time as close to the end of the function as possible
            if ($cmd === static::CMD_START) {
                $mt = microtime();
            }

            // split the time into components
            list($usec, $sec) = explode(' ', $mt);

            // typecast them to the required types
            $sec = (int) $sec;
            $usec = (float) $usec;
            $usec = (int) ($usec * static::USECDIV);

            // create the array
            $time = array(
                $cmd => array(
                    'sec'   => $sec,
                    'usec'  => $usec,
                ),
            );

            // add a time entry depending on the command
            if ($cmd == static::CMD_START) {
                array_push(static::$_queue, $time);

            } else if ($cmd == static::CMD_STOP) {
                $count = count(static::$_queue);
                $array =& static::$_queue[$count - 1];
                $array = array_merge($array, $time);
            }
        }