The e-commerce giant on Wednesday announced that Amazon Prime same-day delivery and free one-day shipping is now available in more than 8,000 cities. Amazon didn’t say how many cities offered speedy shipping before Wednesday’s announcement, making it unclear how much the company has expanded the program for the holidays.

Additionally, Amazon has promised last-minute shoppers that certain orders placed just before Christmas can be delivered on the same day, just in time to put under the tree.. Here’s a quick rundown of the company’s holiday shipping promises.

• Dec. 15: Free shipping for all customers on items fulfilled and shipped by Amazon
• Dec. 18: Last day for standard shipping; free for Prime members only
• Dec. 22: Last day for two-day shipping; free for Prime members only
• Dec. 23: Last day for one-day shipping; free for Prime members only
• Dec. 24: Last day for same-day delivery, as long as an order is placed by 9:30 a.m. local time; free for Prime members

Amazon added that customers will be able to shop at Whole Foods Market and Amazon Books stores on Christmas Eve.

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But before you get too excited, keep in mind that Amazon doesn’t control some of the logistics for actually delivering many orders. Those delivery companies, including UPS, DHL, and others, have reported that the influx of holiday packages has caused some delays, raising the possibility that some packages may not arrive in time.