Royal Caribbean International has decided to squeeze in one more revenue cruise for the Allure of the Seas by scheduling its inaugural sailing one week earlier than planned.

The ship’s first revenue voyage will be a seven-night Caribbean cruise that sets sail from Fort Lauderdale on Dec. 5, 2010.

Customers booked on the Dec. 12 cruise can opt to switch to the new inaugural sailing. They can get the same stateroom and category if they rebook before the end of February. The cruise fare will be the lower of the fare paid or current prices.

The 5,400-passenger Allure of the Seas is sister ship to the Oasis of the Seas, the world’s largest cruise ship.