Usually 60 minutes before park opening on Sunday, Monday, Wednesday, and Friday (Magic Mornings in California Adventure), and 90 minutes before park opening on Tuesday, Thursday, and Saturday (Magic Mornings in Disneyland).
I agree with the above answers. An hour before and "closes" 3 hours before park closing.
It varies. The parking structures generally open one hour before the park. You find the daily park hours on the Disneyland website.
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