Inside of a National Park, there are often limitations to what you can do. So you might not find the activities you are expecting.   But holiday periods are still usually busy, and you should try to plan ahead, especially if you want to stay in or around the park. 

Easter

At the south rim (the north rim doesn't open until mid-May), there is an annual, multi-denominational sunrise service at the rim. This popular event is held at Mather Point. Parking is not allowed at the point for the service, so a special shuttle takes particpants from the lodges inside of the park to  the worship site. if you are staying outside of the park, check with your hotel to see if they have transportation available, or drive into the park and park near one of the lodges. Don't wait until the last shuttle as it usually fills up quickly. 

Memorial Day

A busy time. Visitors to the south rim might want to visit the Grand Canyon Cemetary, adjacent to the Shrine of the Ages.  

Fourth of July

The south rim community has a parade and fundraising auction each year, outside of the park in Tusayan, on State Rt 64. It's hot out there on the highway, so some floats will spray water on the crowd, and some crowd members will spray the floats, hence the marchers carrying signs alongside some of the entries that say either "water" or "NO WATER!" (some folks with antique cars don't appreciate getting sprayed after spending countless hours polishing their vehicles).

Fireworks are not allowed at the Grand Canyon at any time. The closest towns with fourth of July fireworks are Williams AZ, 60 miles/1 hour due south of the south rim, Flagstaff AZ, 90 miles southeast of the south rim, and to the northeast is Page AZ, with fireworks over Lake Powell. There has also been the occasional fireworks display, 30 miles south of the south rim in Valle, which was held as a fund raiser for their volunteer fire department. The may or may not repeat this in future. Please be aware that these are in heavily forested areas of the state. It is not unheard of for firework displays to be cancelled due to dangerously dry conditions in these forests.

Labor Day

Another busy time. Usually signifies that some of the seasonal businesses outside of the park may be closing soon.

Thanksgiving

All of the restaurants inside of the park at the south rim have special menus, or have a turkey dinner selection in addition to their regular menu.

Christmas

You won't see decorations on the outside of the buildings in the park, but all of the hotel lobbies will have holiday decorations. All of the restaurants inside of the park at the south rim  have special menus, or have a turkey dinner selection in addition to their regular menu on Christmas day.

New Year's Eve

At El Tovar, the dining room hosts a dinner/dance which is part of a package for guests of the hotel and staying at Kachina Lodge. Most of the hotels outside of the park also have special dinner parties or menus in their dining rooms, and packages may be available.