And while the foods they eat and drink when the sun is down may vary from culture to culture — there are 1.6 billion Muslims in the world, according to Pew Research Center, spanning every inhabited continent — most will break the fast with dates.
"This is basic in every society," says Abassie Jarr-Koroma, librarian and tour guide at the Islamic Center of Washington, D.C. "Every society has their own traditions. But the main one is the dates."
The tradition springs in part from the Prophet Muhammad's habit of breaking his own fast with dates, says Jarr-Koroma. But the fruit also offers practical physiological effects. After not eating or drinking all day, the body is depleted of nutrients. Dates deliver a hit of energy-boosting carbohydrates, tempered by fiber, which makes them burn more slowly, says Lori Zanini, spokeswoman for the Chicago-based Academy of Nutrition and Dietetics.
Translation: They won't make you crash the way a candy bar will.
"From a dietitian's perspective, it's a great source of carbohydrates, which are the main source of energy for our bodies," Zanini says. "It has no fat, no cholesterol, no sodium. It's just a quick source of energy with a lot of vitamins, minerals and nutrients, as well."
Dates go back centuries in the Middle East, and today that region still leads the world's production. Nearly all dates produced in the United States come from the dry lands of Southern California and Arizona. Production is small, according to government figures, about 33,000 tons in 2011 — one one-hundredth the amount of apples produced.
Dates are eaten in only 5 percent of U.S. households, says John Haydock, global vice president of sales for Datepac, the processing and sales arm of the Bard Valley Medjool Date Growers Association. But sales spike during Ramadan.
"We see it all over the country," Haydock says. "But in certain parts of the country where there's a higher Muslim population, consumption just goes through the roof."
In the U.S., only Christmas sales are higher than Ramadan, he says, and only by a small margin.
During Ramadan, many restaurants that follow Muslim dietary laws set bowls of dates on the tables, Sarmast says. Some also offer jellab, a drink made from date molasses and water, and garnished with pine nuts.
At Al-Ameer in Dearborn, Michigan, owner Abbas Ammar makes sure jellab goes to everyone waiting for dinner.
"That's the drink of choice aside from water," Ammar says. "At our restaurant, we have a line at the door during Ramadan, and we pass it out for people to break their fast, to whoever's in line, Muslim or non-Muslim."
Michele Kayal is co-founder of the website American Food Roots: www.americanfoodroots.com/ . Follow her at @AmerFoodRoots