As people said, PK hours are the same as the school.
The school hours are explained on the school's website (copied below). Official school hours are 8:40-3:15. No (regular) early pickup. PK3 does have quiet time/naps; call the school if you want details. Note that the information about location is specific to this year, when Maury is at Eliot Hine during their renovation.
https://mauryelementary.com/facts/
Daily Schedule
7:15 AM
Polite Piggy’s opens for before care.
8:15 AM
School opens for breakfast. PK3/PK4 students report to the the early childhood breakfast room in Trailer C; Kindergarten–Grade 5 students report to multipurpose room.
8:40 AM
Bell rings; the school day begins. Kindergarten–Grade 5 classroom teachers escort their students from the playground or multipurpose room. Instruction begins.
Students arriving after 8:55 AM must report to the security desk/office for a “tardy slip” before going to the classroom.
Midday
Recess/Lunch (see schedules)
3:15 PM
Bell rings; students are dismissed. Polite Piggy’s aftercare and afterschool activities begin.
6:00 PM
Polite Piggy’s closes.
6:30 PM
School closes. (Please note that the building is available for meetings from 6:30 PM to 8:30 PM Monday–Friday, by arrangement with the main office.)