Image source: Disney. 

Anyone who has been to Walt Disney's (DIS -1.41%)  Animal Kingdom theme park in recent months has seen the heavy construction activity taking place behind the scenes. Mechanical cranes and a "floating mountain" are visible above the greenery as one enters the parking lot, building out the park's ambitious Avatar-themed land that will open next year.

On a less costly but potentially more impactful note, it's impossible to miss the walled-off lake approaching the Asia section of the park where crews are busy putting the finishing touches on an amphitheater that will host the park's upcoming nighttime show. When Rivers of Light opens -- and Disney announced on Wednesday that the nightly celebration will officially debut on April 22 -- guests will be able to see an outdoor show where choreographed music sequences, illuminated lanterns, and projections on water screens come together in paying tribute to the world's wildlife.

It's not a coincidence that the new show will kick off on Earth Day, exactly 18 years after the park officially opened on Earth Day in 1998. The only real shock is that it took the theme park giant this long to realize that it can consistently entertain guests after sundown. 

In its present state, Disney realizes that Animal Kingdom isn't a full-day destination. It closed earlier tonight at 6 p.m., rivaling your far-less-expensive local zoo or science museum on the operating calendar. Until just a couple of years ago, it was Disney World's least visited park, eventually surpassing Disney's Hollywood Studios in annual attendance because that park was being even more neglected by the media giant. 

Things are changing. As a show that needs darkness to strut its visual stuff, you are unlikely to ever see another 6 p.m. closing of the park come April 22. Instead of folks bolting for the exits in the mid-afternoon when the Florida heat or the park's lack of rides drives guests elsewhere, Animal Kingdom's visitors will keep trickling in as the hours pass -- helping Disney cash in on tourists spending big bucks on dinner restaurants, drinks, and illuminated trinkets like the rest of its theme parks.

Next month's seemingly simple nighttime show will be a game changer. It will be the catalyst for other unique post-sunset experiences that Disney has in store. The park's Tree of Life centerpiece will light up. Its signature safari ride will offer nighttime excursions highlighting nocturnal creatures. All of this will be enhanced through lively open-air entertainment experiences. 

The hours-extending upgrades next month will make the park more magnetic, and that's even before Avatar's Pandora opens next year. When that new land debuts in 2017, guests at a park with few actual rides will be able to take a boat ride on the film's Na'vi river or opt for a thrill ride by going flying on a banshee.

I was one of the park's loudest critics during the park's first few years, culminating in a scathing and perhaps unfair critique penned nearly a decade ago. The park offers some of the most stylistic themed elements of any Disney park, but in terms of tourists getting the most bang for their buck, it was hard to deny the exodus that would routinely take place early in the afternoon. Disney has done a good job of changing that, and starting next month it will take the first of two big steps to doing a great job of changing that. 

We've seen Animal Kingdom go from entertaining just 7.3 million annual guests a dozen years ago to 10.4 million visitors in 2014, according to industry tracker Themed Entertainment Association. That record tally will be obliterated with every passing year, and it starts next month with a nighttime show put out by a theme park titan where nocturnal celebrations are part of its pedigree.