The clock is counting down—in some cases literally—for online retailers’ guarantees that orders will arrive in time for Christmas Day. And a number of retailers are driving that message home in their marketing emails, as well as on their websites and apps.

For example, two-day shipping, membership-based ecommerce network ShopRunner sent an email on Tuesday alerting its members to the final dates that merchants will guarantee delivery by Christmas Eve with the subject line, “Shipping cutoffs are here!” The email listed eight merchants with cutoff dates that ranged from Dec. 17 to Dec. 22.

Brooks Brothers, No. 188 in the 2019 Digital Commerce 360 Top 1000, on Wednesday sent an email to consumers with the subject line, “Free shipping ends today. Order by noon ET for Christmas delivery.” And Ann Taylor, which is owned by Ascena Retail Group (No. 81), sent an email on Sunday with the subject line, “F.I.N.A.L.H.O.U.R.S” that prominently featured a box that counted down the hours that consumers could place an order with standard shipping for guaranteed delivery by Christmas Eve. 

Other merchants acknowledged that the deadline for guaranteed delivery by Dec. 24 had passed but sought to find creative ways to capture a sale. Heirloom bean retailer Rancho Gordo New World Specialty Food, for example, sent an email on Tuesday with the subject line, “Rancho Gordo News: You Blew It! (But We Can Still Help)” that stated, “You blew it! It’s too late for ground shipping. No judgments from us. We know exactly how hard it is to enjoy the season, see your friends, and get just the right gift. Life just gets in the way sometimes. Instead of lamenting your fate, let’s take action. A Rancho Gordo Gift Card is appreciated by all lovers of good food. Let them decide what they’d like. It works online or at our Napa store. We’ll show them a good time, either way.”

However, an analysis of the cutoff deadlines among the 50 largest online retailers in North America conducted by Digital Commerce 360 found little uniformity in retailers’ presentation of their shipping deadlines. Some merchants, such as Estee Lauder (No. 49), prominently displayed on its homepage on Wednesday Dec. 18 that “We’re still delivering,” and then noting in capital letters its deadline for free holiday delivery is Dec. 19 at 3 p.m. EST.

Similarly, Amazon (No. 1) noted in the right-hand corner of its website a hyperlink to “Get items by 12/24.” When a shopper clicks the link, he’s taken to a page that tells him Wednesday Dec. 18  was the last day for free shipping by Amazon with guaranteed delivery by Dec. 24, and Thursday, Dec. 19 is the last day for standard shipping. Amazon set separate deadlines for members of its Prime loyalty program; Sunday Dec. 22 is the last day for free delivery with Prime, Monday Dec. 23 is the last day for Prime’s free one-day delivery.

Retailers likely based their deadlines on the significant number of packages that failed to arrive on time last year. During the 2018 holiday season, 6% of packages shipped on Dec. 19 failed to arrive on time, 6% of packages shipped on Dec. 20 failed to arrive on time, 8% of packages purchased online on Dec. 21 weren’t delivered in time for Christmas and 11% of packages purchased online on Dec. 22 were late, according to data gathered by Convey, a last-mile delivery software vendor.

Convey’s data is based on tens of millions of packages shipped from more than 500,000 U.S. locations across the company’s client base. The vendor has 130 retail clients in many merchandise categories, including retailers Home Depot (No. 7), Neiman Marcus (No. 50), Eddie Bauer (No. 161) and Jet.com (No. 24 in the 2019 Digital Commerce 360 Online Marketplaces database).

“It’s easy to understand how challenging on-time delivery is,” says Rob Taylor, Convey’s CEO. “Add to that fewer shopping days between Thanksgiving and Christmas this year plus the usual chance of winter weather wreaking havoc on the supply chain, it’s never been more difficult for retailers to get packages under the tree on time.”

Setting clear expectations for consumers is important, says Lauren Freedman, senior consumer insights analyst for Digital Commerce 360. “Conveying that information prominently on a retailer’s site and via all marketing emails is optimal,” she says. “Retailers should also be prepared to communicate early and often if something goes wrong or the weather fails to cooperate.”

Even so, a number of Top 50 merchants made it difficult to find their cutoff dates. Ikea, No. 37, doesn’t mention its delivery cutoff date anywhere on its homepage. And a shopper has to navigate to checkout, enter his state and ZIP code to determine the cost of delivery. Similarly, Lowe’s (No. 23) also doesn’t mention delivery by Christmas Eve.

Some store-based merchants will likely drive consumers to their stores to avoid potential shipping slip-ups. Saturday is anticipated to be the biggest shopping day of the holiday season with 147.8 million U.S. consumers expected to shop online and offline, according to a survey conducted by the National Retail Federation and Prosper Insights & Analytics. That’s 13.5 million more consumers than the number who shopped during the Saturday before Christmas last year.

That largely reflects that a share of consumers started their holiday shopping later than last year thanks in part to six fewer shopping days after Thanksgiving than last year. As of early December, 86% of consumers had started their shopping, and they had completed 52% of their purchasing for the season, NRF’s survey found. At the same point last year, 88% of consumers had started their shopping, and they had completed 58% of their purchasing. 

“Those who waited until Thanksgiving weekend are feeling the pressure due to the limited number of days this year between Thanksgiving and Christmas,” says Matthew Shay, NRF president and CEO.