core-bundle/src/Resources/contao/controllers/FrontendCron.php
protected function hasToWait()
	{
		$return = true;

		// Get the timestamp without seconds (see #5775)
		$time = strtotime(date('Y-m-d H:i'));

		// Lock the table
		$this->Database->lockTables(array('tl_cron'=>'WRITE'));

		// Get the last execution date
		$objCron = $this->Database->prepare("SELECT * FROM tl_cron WHERE name='lastrun'")
								  ->limit(1)
								  ->execute();

		// Add the cron entry
		if ($objCron->numRows < 1)
		{
			$this->Database->query("INSERT INTO tl_cron (name, value) VALUES ('lastrun', $time)");
			$return = false;
		}

		// Check the last execution time
		elseif ($objCron->value <= ($time - $this->getCronTimeout()))
		{
			$this->Database->query("UPDATE tl_cron SET value=$time WHERE name='lastrun'");
			$return = false;
		}

		$this->Database->unlockTables();

		return $return;
	}
protected function hasToWait()
	{
		$return = true;

		// Get the timestamp without seconds (see #5775)
		$time = strtotime(date('Y-m-d H:i'));

		// Lock the table
		$this->Database->lockTables(array('tl_cron'=>'WRITE'));

		// Get the last execution date
		$objCron = $this->Database->prepare("SELECT * FROM tl_cron WHERE name='lastrun'")
								  ->limit(1)
								  ->execute();

		// Add the cron entry
		if ($objCron->numRows < 1)
		{
			$this->Database->query("INSERT INTO tl_cron (name, value) VALUES ('lastrun', $time)");
			$return = false;
		}

		// Check the last execution time
		elseif ($objCron->value <= ($time - $this->getCronTimeout()))
		{
			$this->Database->query("UPDATE tl_cron SET value=$time WHERE name='lastrun'");
			$return = false;
		}

		$this->Database->unlockTables();

		return $return;
	}
Check whether the last script execution was less than a minute ago

@return boolean