Valentine’s Day falls just a heartbeat behind Mother’s Day among restaurants’ busiest days of the year, and with it comes operational heartaches.

In years past, the National Restaurant Association has estimated that as many as 70 million people will dine out on Valentine’s Day, surpassing No. 3 Father’s Day, No. 4 New Year’s Eve and No. 5 Easter.

The Feb. 14 holiday falls on a Friday this year, raising the potential for a tsunami of love-struck guests, from bastions of high-dollar fine dining to the kitsch of White Castle.

“What’s the saddest day of the year for a restaurant that has all four-tops?” asked Sherri Kimes, Cornell University professor of services operations management, referring to the challenges of accommodating the wave of two-person parties on Valentine’s Day.

“What are you going to do? Tell the next couple that walks in that, ‘There's a lovely couple over there at that table, would you like to join them?’” Kimes said.

Operators can prepare for the onslaught of two-by-two parties, starting by estimating how many two-tops they expect.

Using data from prior-year holidays, “What a restaurateur should do is estimate the percentage of parties that will come in as parties of two and multiply the number of seats in the restaurant by that percentage,” Kimes said. “That will give the number of seats that should be provided at two-tops.” To calculate the number of tables, divide that number by two.

“Let's say a restaurateur estimates that about 80 percent of parties on Valentine's Day come as couples,” Kimes explained. “Her restaurant has 200 seats: 80 percent of 200 equals 160 seats should be at two-tops.” Divide 160 by two, she added, and the operator should budget 80 two-tops.

The Valentine’s Day two-top percentage depends on the type of restaurant, Kimes said.

“I’ve seen some fine-dining restaurants where it’s 90 percent [two-tops],” she said, adding with a laugh, “and there are no singles.”

Kimes advised operators to acquire more two-top tables if possible by switching out four-top and larger tables with two-tops rented, borrowed or on hand for the occasion.

“You might have some in the back, or maybe you can borrow some,” she said. “If you don’t have a lot of two-tops and you are taking reservations, you might want to be giving preference to the larger parties if you have the excess demand.”

Tables that allow seating flexibility are crucial to restaurant planning, Kimes said, as other holidays, such as Mother’s Day, pose the opposite challenge of Valentine’s Day: a demand by large parties and bigger tables.

Valentine’s Day also offers the potential for significant upselling, even before guests enter the door, Kimes added.

“You can have special Valentine’s Day menus that may be a little pricier, because people want something special,” she said. “You also have the possibilities for add-on sales for flowers or something like that. When the restaurant takes a reservation, it might be worth asking questions about doing extra things. Customers might value that and, of course, would be willing to pay for.”

In 2011 the NRA surveyed member restaurants and found the best guest responses to special menu items, prix fixe menus, celebratory beverages or desserts, flowers or candy, and entertainment or music.