Disneyland Park and Disney California Adventure will welcome guests back on April 30 with restricted capacity and new rules. Those with preexisting theme park tickets can take a peek at the reservation calendar on Friday ahead of new ticket bookings, according to a blog post to Disney’s Park blog. Disneyland Park and Disney California Adventure will welcome guests back on April 30. (iStock) Starting Friday, anyone with an active theme park ticket can check available days to reserve via the Disneyland Parks website. The theme park reservation system will launch on April 12 for guests with existing valid theme park tickets to start booking. Disneyland is also extending expiration dates of many tickets as a result of the closure, too.