Twenty percent of shoppers don’t plan on finishing their shopping until after December 23, according to a recent Consumer Reports Holiday Shopping Poll. That's too late to ship gifts to most recipients if you want them to arrive by December 25 (though some retailers, such as Amazon.com, can accomodate late shoppers, for a price).

Here are the ground shipping deadlinesfrom Fed Ex, UPS, or the United States Postal Service (USPS).

Another important date for shoppers: Friday, Dec. 17. It’s the third annual free shipping day, and more than 1,100 retailers are participating, ranging from Ann Taylor Loft to Zales. All of the retailers offer free shipping with delivery by Christmas Eve, according to site creator Luke Knowles. Worried you’ll forget? You can sign up at freeshippingday.com for an email reminder on December 17. The site also offers the holiday shipping deadlines for more than 120 retailers. You can also check out freeshiping.org for promotion codes to use if you’re hoping to take advantage of current online sales.