If I execute the following query on MariaDB 10.1 or later, the result contains a column with a datetime field type (MYSQL_TYPE_DATETIME):
`SELECT MIN(NOW()) AS t`
On older versions or any version of MySQL this column is a text type (MYSQL_TYPE_VAR_STRING).
I'm not aware of a sql_mode compatibility flag so I consider this a bug.
I see why it's preferable/reasonable to return a datetime, but this behavior breaks existing applications.