There are 5 levels of
Disneyland APs: SoCal Select, SoCal Deluxe, Deluxe, Signature, and Signature Plus (plus Premier which is for both parks). Signature Plus is 365 days a year, Signature blocks out the two weeks surrounding Christmas. Deluxe is what a lot of locals get; during the summer they are blocked out on Saturdays, plus other days throughout the year! The SoCal ones are much cheaper but insanely limited for blockout dates, most weekends and basically the entire summer.
Excluding the christmas weeks, the lower crowd days end up being those where Deluxe passes are blocked out. So Saturday summers are much much better than Sundays. Weekdays, you will have higher crowds in evening once locals finish school/work, much more pronounced than at WDW. Even though the Deluxe passes are not blocked out during your trip, it shouldn't be too bad. The worst weekends are late spring/early fall, where all the locals are trying to go before their passes get blocked out.