CIBlockPropertyDateTime::ConvertToDB

static function ConvertToDB($arProperty, $value)
{
	$dateTimeValue = (string)($value['VALUE'] ?? '');
	if ($dateTimeValue !== '')
	{
		if (!static::checkInternalFormatValue($dateTimeValue))
		{
			try
			{
				$time = BitrixMainTypeDateTime::createFromUserTime($dateTimeValue);

				$value['VALUE'] = $time->format(static::FORMAT_FULL);
			}
			catch (BitrixMainObjectException $e)
			{
			}
		}
		else
		{
			$value['VALUE'] = $dateTimeValue;
		}
	}

	return $value;
}