It varies day to day. To complicate things, Magic Morning (attached to many 3+day tickets) is only for Disneyland's days. Early Magic Hour is for on-site guests each day of their stay, and allows whatever park is open for MM/EMH that day. So if you stay on-site, you can get in early to whatever park is assigned that day. But if you are off-site and using your ticket, you get into Disneyland on the assigned day once during the use of your ticket.Do both parks have early entry? do they each have their own early entry days?
EE/Magic Morning at Disneyland: days with a T in them: Tuesday, Thursday, Saturday.
EE at California Adventure: Sunday, Monday, Wednesday, Friday