calendar-bundle/src/Resources/contao/dca/tl_calendar_events.php
public function setEmptyEndTime($varValue, Contao\DataContainer $dc)
	{
		if ($varValue === null)
		{
			$varValue = $dc->activeRecord->startTime;
		}

		return $varValue;
	}
public function setEmptyEndTime($varValue, Contao\DataContainer $dc)
	{
		if ($varValue === null)
		{
			$varValue = $dc->activeRecord->startTime;
		}

		return $varValue;
	}
Automatically set the end time if not set

@param mixed                $varValue
@param Contao\DataContainer $dc

@return string