To visit Disneyland Park or Disney California Adventure in 2026, you must secure a theme park reservation in addition to your ticket. The booking window for these reservations generally opens 120 to 180 days in advance for standard ticket holders, while Magic Key pass holders have a shorter rolling window (often 90 days). When a new block of dates is released, the system typically updates at 6:00 AM PT (9:00 AM ET). However, availability can shift throughout the day as guests cancel or modify their plans. It is highly recommended to log into your Disney account a few minutes early to ensure you are ready the moment the clock strikes 6:00 AM, especially for high-demand periods like Spring Break, Halloween Time, or the December holidays. If you are purchasing a new ticket, the reservation process is usually integrated into the checkout flow, but for multi-day tickets or pass holders, you must manually select each day via the "My Disneyland" section of the official website or the Disneyland mobile app.