TimeManager::start

public function start($taskId, $stopPrevious = false)
{
	$result = array();

	if($taskId = $this->checkTaskId($taskId))
	{
		global $USER;

		$timer = CTaskTimerManager::getInstance($USER->getId());
		$lastTimer = $timer->getLastTimer();
		if(!$stopPrevious && $lastTimer['TASK_ID'] && $lastTimer['TIMER_STARTED_AT'] > 0 && intval($lastTimer['TASK_ID']) && $lastTimer['TASK_ID'] != $taskId)
		{
			$additional = array();

			// use direct query here, avoiding cached CTaskItem::getData(), because $lastTimer['TASK_ID'] unlikely will be in cache
			list($tasks, $res) = CTaskItem::fetchList($USER->getId(), array(), array('ID' => intval($lastTimer['TASK_ID'])), array(), array('ID', 'TITLE'));
			if(is_array($tasks))
			{
				$task = array_shift($tasks);
				if($task)
				{
					$data = $task->getData(false);
					if(intval($data['ID']))
					{
						$additional['TASK'] = array(
							'ID' => $data['ID'],
							'TITLE' => $data['TITLE']
						);
					}
				}
			}

			$this->errors->add('OTHER_TASK_ON_TIMER', 'Some other task is on timer', false, $additional);
		}
		else
		{
			if($timer->start($taskId) === false)
			{
				$this->errors->add('TIMER_ACTION_FAILED.START', 'Timer action failed');
			}
		}
	}

	return $result;
}