The number crunchers at TripAdvisor have done the math and come up with a few guidelines on the best time to book hotels for the winter holidays.

For hotel stays in the US, for example, it’s best to hold off and book in November, when hotel rates are up to 20% less than the highest annual prices, experts say.

For the guideline, experts analysed historical hotel booking and interest in nine popular regions around the world for the last two weeks of December. The best time to book was defined as periods when hotel prices were less than average for the destination.

Here are a few recommendations:

Thinking of ringing in the New Year in the City of Light? Best times to find deals is the beginning of March or by mid-November.

Booking after September can save travelers 16% versus the peak rate.

Hotel prices remain steady throughout the year.

Middle East and Africa
Prices were seen to drop 17% starting in November for the Middle East, and 10% for Africa.

South America 
Travelers are advised to book after September.

South Pacific
Booking in September and late November can save travelers 10%.