core-bundle/src/Resources/contao/library/Contao/Date.php
protected static function resolveCustomModifiers($strDate)
	{
		if (strpos($strDate, '::') === false)
		{
			return $strDate;
		}

		System::loadLanguageFile('default');

		if (!$GLOBALS['TL_LANG']['MSC']['dayShortLength'])
		{
			$GLOBALS['TL_LANG']['MSC']['dayShortLength'] = 3;
		}

		if (!$GLOBALS['TL_LANG']['MSC']['monthShortLength'])
		{
			$GLOBALS['TL_LANG']['MSC']['monthShortLength'] = 3;
		}

		$strReturn = '';
		$chunks = preg_split("/([0-9]{1,2}::[1-4])/", $strDate, -1, PREG_SPLIT_DELIM_CAPTURE);

		foreach ($chunks as $chunk)
		{
			list($index, $flag) = explode('::', $chunk);

			switch ($flag)
			{
				case 1:
					$strReturn .= $GLOBALS['TL_LANG']['DAYS'][$index];
					break;

				case 2:
					$strReturn .= $GLOBALS['TL_LANG']['DAYS_SHORT'][$index];
					break;

				case 3:
					$strReturn .= $GLOBALS['TL_LANG']['MONTHS'][($index - 1)];
					break;

				case 4:
					$strReturn .= $GLOBALS['TL_LANG']['MONTHS_SHORT'][($index - 1)];
					break;

				default:
					$strReturn .= $chunk;
					break;
			}
		}

		return $strReturn;
	}
protected static function resolveCustomModifiers($strDate)
	{
		if (strpos($strDate, '::') === false)
		{
			return $strDate;
		}

		System::loadLanguageFile('default');

		if (!$GLOBALS['TL_LANG']['MSC']['dayShortLength'])
		{
			$GLOBALS['TL_LANG']['MSC']['dayShortLength'] = 3;
		}

		if (!$GLOBALS['TL_LANG']['MSC']['monthShortLength'])
		{
			$GLOBALS['TL_LANG']['MSC']['monthShortLength'] = 3;
		}

		$strReturn = '';
		$chunks = preg_split("/([0-9]{1,2}::[1-4])/", $strDate, -1, PREG_SPLIT_DELIM_CAPTURE);

		foreach ($chunks as $chunk)
		{
			list($index, $flag) = explode('::', $chunk);

			switch ($flag)
			{
				case 1:
					$strReturn .= $GLOBALS['TL_LANG']['DAYS'][$index];
					break;

				case 2:
					$strReturn .= $GLOBALS['TL_LANG']['DAYS_SHORT'][$index];
					break;

				case 3:
					$strReturn .= $GLOBALS['TL_LANG']['MONTHS'][($index - 1)];
					break;

				case 4:
					$strReturn .= $GLOBALS['TL_LANG']['MONTHS_SHORT'][($index - 1)];
					break;

				default:
					$strReturn .= $chunk;
					break;
			}
		}

		return $strReturn;
	}
Resolve the custom modifiers

@param string $strDate The date string

@return string The resolved date string