PETERSON AIR FORCE BASE, United States-Depending on which country they're from, the kids may ask about Father Christmas, Papa Noel, Saint Nick or Santa Claus.
But those who believe, all want to know one thing: Where in the world the jolly old man and his sleigh full of gifts are on Christmas Eve.
For the 64th time, a popular program run by the US and Canadian militaries is providing real-time updates on Santa's progress to millions around the globe.
And this year, the North American Aerospace Defense Command, or NORAD, is offering even more high-tech ways for children and parents to follow along.
Operation NORAD Tracks Santa has evolved from a misdirected telephone call in 1955 to a trailer parked outside the command's former lair deep inside Cheyenne Mountain, Colorado, and then to NORAD's modern-day headquarters at Peterson Air Force Base in the same state.
Along the way, the tens of thousands of telephone calls fielded by NORAD volunteers each year have been augmented by an explosion of technology that lets millions track St. Nick's journey from the North Pole to the Pacific and Asia, from Europe to the Americas.
This year's information portals include Alexa, OnStar, Twitter, Facebook, Instagram and 3D apps developed for mobile devices by Cesium, a Philadelphia-based IT and defense contractor. The apps integrate geospatial and satellite-positioning technology with high-resolution graphics that display the actual positions of the stars, sun and moon and the shadows they cast at any point in Santa's journey.
It takes a village of dozens of tech firms-including Google, Microsoft, Hewlett Packard and Bing Maps-to deliver the immersive effect for global Santa trackers. There were some 15 million visits to the website last year alone.
And it takes a village of 1,500 volunteers to field emails and the 140,000 or so telephone calls to 1-877-HI-NORAD, which translates numerically to 1-877-446-6723. The volunteers staff phone banks, equipped with monitors, inside a building at Peterson, which offers a view of snow-capped Pikes Peak to the west.
More volunteers and firms donate food, water and coffee to those on Santa Watch.
"Hi Santa Trackers! Lots of kids are waiting to ask you about Santa," a sign reads.
Volunteers are equipped with an Operations Center Playbook that helps ensure every caller can go to sleep happy and satisfied on Christmas Eve.
Longtime Santa trackers are familiar with the NORAD-Santa story.
In 1955, Air Force Colonel Harry Shoup-the commander on duty one night at NORAD's predecessor, the Continental Air Defense Command-fielded a call from a child who dialed a misprinted telephone number in a newspaper department store ad, thinking she was calling Santa.
A fast-thinking Shoup quickly assured his caller that he was. And a tradition was born.
Today, most early calls come from Japan and Europe. The volume soars in the US and Canada, said program manager Preston Schlachter. United Kingdom callers ask about Father Christmas. Those in France generally seek Papa Noel's whereabouts.
For team members, once "Big Red"-Santa's code name-is airborne, Schlachter said, "it's off to the races."
"I've never had a block of time move so quickly," he said.