Timezone issue in 

Relates to #9403.

In BaseDateTimeTransformer constructor we need to check if timezone is valid. See code below to see an issue.

DateTimeZone object creation could rise an exception. And this exception is catched and rethrowed as TransformationFailed exception.

So user will see "Invalid value" error. But issue is actually with php configuration or form type configuration.

https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToArrayTransformer.php#L176