NEW YORK: On Christmas morning, millions of people will unwrap new iPads, iPhones andiPod Touches – and immediately start downloading games and other applications for them. It is the biggest day of the year for app sales, which can mean big money for developers.

That is, if they manage to get their apps through Apple’s review process and into the App Store before everyone at Apple goes on vacation. Each year around Christmas, Apple stops accepting app submissions and updating its store for a while.

This year the shutdown starts on Thursday and runs for eight days. In the weeks leading up to the cutoff, developers often pull all-nighters so they can get their work to Apple in time. “There’s a mad scramble for developers,” said Marc Edwards, lead designer at Bjango, an Australian app maker.

“In terms of money, it can be a really big deal.” It is hard to begrudge Apple for wanting to give its employees a break. But the App Store freeze at Christmas, and the crunch time leading up to it, underscores Apple’s power in the world of mobile apps and the lengths developers are willing to go to meet its demands.

In short, Apple is a powerful gatekeeper, and for more than a week it is keeping the gate closed. “If you are a developer and want to sell an app for the iPhone, you have to go through Apple,” said Charles S Golvin, an analyst at Forrester Research who tracks the wireless industry. “That’s not true of Android or most other outlets,” he added.

“I can’t think of another company that has such a dominant lock on the channel to sell to an audience.” Android, the smartphone software made by Google, has the second-biggest app economy after Apple . And it does not have Apple’s stringent and sometimes inscrutable board of testers and reviewers, who can reject any app that, in their judgment, does not meet the company’s technical or content standards.

Android developers can sell their apps through a variety of third-party outlets like Amazon .com and GetJar, as well as the Google-run Android Marketplace, which is happy to accept new apps any day of the year.

But developers say that although Android phones are now bigger sellers than iPhones, it is still more lucrative to build apps for Apple products. The stakes are higher than ever this year because AT&T is no longer the only carrier in the United States selling the iPhone, so there are more potential customers.

Apple declined to comment on the App Store freeze. Bryan Duke, a part-time app developer inLas Vegas, has seen firsthand how much of a difference one day can make. One of his apps is an air hockey game that costs 99 cents and usually averages about 300 downloads a day.

But on Christmas Day last year there were 1,834. Apple keeps 30% of the revenue. “It’s typical to see a jump on any major holiday, but Christmas is the biggest one,” Duke said. “I’m certainly hoping for a nice big Christmas bump this year.” Flurry, a mobile analytics firm, estimated that from December 23 to 26 last year, 240 million applications were downloaded to Apple mobile devices, or about 20% of the total downloads for the month.

The promise of a Christmas bonanza was enough to motivate David Barnard, the founder of App Cubby, a developer in Austin, Texas, to jump into creating a notifications app, just days before the deadline. Barnard and his small team have built apps like Tweet Speaker, which readsTwitter messages aloud, and Mirror, which turns the iPhone screen into a mirror with the help of the front-facing camera.

“If we can get that snowball rolling and get it right, we can ride the momentum,” he said. “We’re going to give it a shot.” John Shahidi, CEO of RockLive, a mobile application developer in Los Angeles, said his company started working on a soccer game in August, with an eye toward Christmas.

“We needed the extra time as insurance to make sure that we are visible in the App Store and have time for any updates,” he said. Inevitably, though, there was a rush at the end. “I can’t tell you the last time I’ve slept eight hours,” he said.

Although Rock-Live’s app, called Heads Up, sailed through Apple’s review process and went on sale this month, Shahidi said he was keeping an eye out for any bugs or problems that might require a software update.