Valentine’s Day is always a boon to the restaurant industry as many couples celebrate by going out for a romantic dinner.

But having the holiday fall on a Monday, as it does this year, is especially good for business, according to many restaurateurs.

“Monday is the best day you can have Valentine’s Day on, because you end up with a strong weekend plus the carryover on Monday,” which is traditionally a slow night, said John Brandt-Lee, chef-owner of Avalon Restaurant in West Chester, Pa.

The National Restaurant Association said Wednesday that 70 million Americans are expected to celebrate Valentine’s Day at a restaurant this year, making Feb. 14 the second most popular holiday for dining out behind Mother’s Day.

Restaurateurs said the timing of Valentine’s Day this year is expected to produce strong sales from Friday through Monday.

“Monday is the best day for us to have it fall on,” said William Jack Degel, chief executive of the three-unit Uncle Jack’s Steakhouse steakhouse in New York City. “It will drive business on Friday, Saturday, Sunday and Monday.”

J. J. Kingery, corporate chef of the three-unit Wild Eggs in Louisville, Ky., said he expects robust Valentine’s Day business starting on Thursday night, and Matt Accordion, chef of SPQR in San Francisco, said the restaurant was already 95 percent booked from Thursday through Monday.

Online reservation service OpenTable confirmed that many consumers were planning to celebrate Valentine’s Day throughout the weekend.

It surveyed more than 4,000 diners, asking when they planned to dine out, on which nights and how much they planned to spend.

Nearly 90 percent of respondents said they planned to dine out for the holiday, with 30 percent planning a Saturday night celebration, compared with 39 percent who planned to eat out on the holiday itself. Fifteen percent said they’d be dining out on Sunday, and 4 percent planned Friday festivities.

Twelve percent of respondents said they’d eat out on more than one day during the weekend, but 19 percent said they wouldn’t be booking their reservations until this week.

About 90 percent said they planned to spend about the same as or more than they did last year. Most respondents, 70 percent, said they had budgeted to spend more than $100, with 12 percent expecting dinner checks to exceed $200.

Jeff Wyatt, owner of Marche Bacchus French Bistro & Retail Wine Shop in Las Vegas, said having Valentine’s Day on a Monday helps attract customers for the entire weekend, including Sunday brunch and dinner.

“We also expect to benefit from enhanced patron volume on Thursday, as some individuals may want to celebrate on a less crowded evening, and Thursday is interpreted by many as the buffer day for the weekend,” he said.

Nancy Oswald, an Atlanta-based owner of nine restaurants across the Southeast, said that Monday and Thursday tended to be the best days for Valentine’s Day.

“When February 14 falls immediately preceding the weekend or immediately following it, the Valentine’s Day celebration is stretched over the corresponding three days,” she said. “From a restaurant operations perspective, this allows us the opportunity to accommodate an increased number of guests.”

Oswald said that doesn’t tend to work for Tuesdays and Wednesdays.

“It appears that the majority of Valentine couples are not as willing to stretch the celebration past the weekend much more than a day either way,” she said. “Valentine’s Days that fall on Tuesdays and Wednesdays are traditionally celebrated primarily on those days.”

Some restaurants are encouraging customers to celebrate all weekend by offering special promotions. The Beehive in Boston has declared the weekend “Four Days of Luvs’n” with special menus and musical performances at brunch and dinner.

Eric Feldman, general manager of 3 Vines Café & Wine Bar in Sleepy Hollow, Ill., said he always starts promoting weekday holiday on the previous weekend.

“We run the same specials every day through the holiday. That way, rather than having only one day to create a buzz and additional business, we have three or four,” he said.

He added that he’d start providing entertainment earlier in the day this Monday, and also take reservations for earlier in the evening.

“We anticipate our guests will be departing between 8:30 and 9:30 p.m., much earlier than on the weekend, yet we will garner similar numbers due to the earlier start,” Feldman said.

Bertucci’s, a 94-unit casual-dining Italian chain based in Northborough, Mass., is offering its Valentine’s Day menu starting on Friday, including “Love Me Tender Shrimp Scampi” — sautéed in Alfredo garlic sauce for $15.99 — and a “Will You Be Mine Filet” — an 8-ounce center-cut beef tenderloin with portobello mushroom sauce, red skin mashed potatoes and asparagus for $20.99. Guests also will get a coupon for free dessert on a future visit.

But not everyone thinks a Monday Valentine’s Day is good for business. Restaurant consultant Michael Desiderio, who had been general manager or chief operating officer at Windows on the World, the Russian Tea Room and Tavern on the Green — all legendary New York venues for celebration in their day — said the Monday timing too closely follows the weekend.

“A lot of people elect to celebrate on Saturday, a night that they might have been going out anyway,” he said. “There’s something about Mondays that makes people cautious about having a big night out, because they’re very conscious of having to work the next day, in a way they don’t seem to be later in the week.”

So at Ponte’s an Italian restaurant in New York where he currently is consulting, he’s offering Valentine’s Day options on both Saturday and Monday.