In the second year of implementation (2022-2023), we evaluate differences in learning gains in a second cohort of students in full- and half-day classrooms. We also follow a subsample of five-year-old Kindergarten (5K) students who had attended full- and half-day 4K in 2021-2022 to assess gains in learning once students leave 4K. This report presents findings from the second year evaluation of learning gains. In addition to assessing gains in achievement over the course of the year, we observed in classrooms and interviewed teachers to examine qualitative differences in instruction, time use, and culturally responsive practices across 4K and 5k. Results from the qualitative analysis are discussed in a separate report. (author abstract)