Walt Disney World and Disneyland made official this morning that their theme parks will start charging different prices for admission on different days of the year, starting tomorrow.

The new seasonal pricing plan will create three pricing tiers for one-day theme park tickets: value, regular, and peak days. Disney will use its crowd calendars to assign days into one of the three price tiers, and single-day tickets now will be assigned to a specific day of use.

The upside is that the new plan will allow visitors who have the flexibility to visit on less crowded days to enjoy a lower-than-usual price for a single day’s visit, as well as the smaller crowds in the park found on such days. The downside is that families with children in school likely will find it even more expensive to visit a Disney theme park, as many school vacation days likely will end up in the peak days tier.

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Of course, most visitors — especially to the Walt Disney World Resort — visit using multi-day tickets. Those tickets will not vary by tier but the prices on them will go up across the board tomorrow, as well.

One day, one-park tickets at Walt Disney World will cost $124 for peak days at the Magic Kingdom and $114 at Epcot, Animal Kingdom and Hollywood Studios. Regular days will cost $110 at the MK and $102 at the other parks. Prices for the value days will remain what they are now — $105 for the Magic Kingdom and $97 for the other three WDW parks.

One day, one-park tickets to Disneyland and Disney California Adventure will cost $119 for peak days, $105 for regular days, and $95 for value days. Those tickets currently cost $99 on all days of the year. There will be 83 value days remaining in 2016 — all weekdays during the school year. And there will be 83 more peak days — during spring break, summer weekends and the holiday season in December.

Earlier this month, Universal Studios Hollywood adopted a dynamic discount system for one-day tickets bought in advance via the park’s website. Universal kept the gate price of daily tickets the same for every day, but offers varying discounts based on the date you commit to visit.

The point of these variable, seasonal, dynamic pricing systems (whatever you wish to call them), is to provide another incentive for people to move their visits from busy days to less-busy ones. That allows the parks to better distribute their capital resources, as they no longer have to build excess capacity for peak periods that sits unused during less busy times.

In addition, peak pricing allows the parks to be more aggressive about admission increases, as these systems allow the park to avoid raising the price on less popular days, when people might not be inclined to visit at the higher prices.

Today’s move leaves Universal Orlando’s theme parks as the only ones among the nine most popular theme parks in the United States not to have some dynamic pricing system for its theme park tickets. Earlier this month, Universal Orlando raised prices for its one-day and multi-day tickets, beating Disney to what’s become the annual late-winter price increases for tickets at major theme parks.

This story originally appeared on Theme Park Insider. It is reprinted here with permission.

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Photo Credit: Disneyland park in Anaheim, CA. Anna Fox / Flickr