pymongoarrow already supports datetime but that is not ideal to store partitioned values. I assume we would ideally store dates as BSON Date in MongoDB and then get back a Parquet Date. Y'all already support many data types (https://github.com/mongodb-labs/mongo-arrow/blob/main/bindings/python/docs/source/data_types.rst). It's just that partitioning by date is very useful for us.