You may want to expand your tests a bit to be sure this works like you think. I kinda remember working on this (or something similar elsewhere in the code and having a discussion with Iccha about it even) early on in qonos and the seemingly extraneous "between" stuff up on line 338 was added because doing it with two separate filters was acting like an OR, not and AND, and so it was returning everything. It needed the explicit "between" clause if you really wanted something between two values.