Notes:
- Introduces the concept of queries on multiple properties (which meant changing query's internals a bit)
- Dates are stored as well as the "reference" in the index to allow quick filtering without fetching the whole entity
- Buckets are weeks starting on Monday (guaranteed by the use of the Julian calendar)
- Some size improvements are definitely possible (dates are padded numbers again, not using integer databases, Julian calendar starts at a very old date, etc.)