Another day, another deal.

Thanks to online coupons, price-comparison search engines and reward memberships, savvy shoppers can pay less than full price on any day that ends in "y." But depending on what you're planning to buy, some days of the week may yield better bargains than others.

We talked to the experts, and narrowed down the best days of the week to buy certain items.

Airplane Tickets

When to Buy:: Wednesday morning

Why:: "Most airfare sales are thrown out there on the weekend," says travel expert Peter Greenberg, a.k.a. The Travel Detective. Other airlines then jump into the game, discounting their own fares and prompting further changes by the first airline. The fares reach their lowest prices late Tuesday or early Wednesday.

Books

When to Buy: Thursday

Why: Price compare between major chains Borders and Barnes & Noble. The former releases its weekly sales and coupons on every Thursday; the latter, every Tuesday.

Cars

When to Buy: Monday

Why: "Car dealers live for the weekend, which is when they make most of their sales," says Phil Reed, consumer advice editor for Edmunds.com. "On Mondays, the low foot traffic makes it seem like the weekend will never come." That dealer desperation, paired with fewer consumers on the lot, give you more negotiating power.

Clothing

When to Buy: Thursday evening

Why: That's the day when stores stock their shelves for the weekend, and when many retailers -- including Ann Taylor, Banana Republic and Express -- start their weekend promotions, says Kathryn Finney, author of "How to Be a Budget Fashionista." You'll find great prices and the best selection. "It's an effort to get people to shop in the middle of the week," she says.

Department-Store Wares

When to Buy: Saturday evening

Why: Department stores have a lot to mark down for their Sunday circulars, so they frequently start the process on Saturday evenings before store closing, says Finney. "They're preparing for the big rush," she says. Bonus: Even if the markdowns haven't been made, many employees will honor the sale price if you ask. Print out the circular preview from the store's web site, and bring it with you when you head to the mall.

Dinner Out

When to Buy: Tuesday

Why: Most restaurants do not receive food deliveries over the weekend. "Sunday is the garbage-can day of the week," says Kate Krader, senior editor at Food & Wine magazine. "No doubt, they're cleaning out their fridges. Tuesdays, they're starting fresh." Dining out on that day offers the best odds you'll get a meal worth paying for, no matter your price point, she says.

Gas

When to Buy: Thursday, before 10 a.m.

Why: The price of oil isn't the only factor influencing costs at your local pump. Consumer usage plays a role, too -- and weekend demand is high, says Jason Toews, co-founder of GasBuddy.com, a price-monitoring site. Prices usually swing upward on Thursdays as travelers fuel up to head out the following day. By hitting the pump before 10 a.m. (when many station owners change their prices), you'll beat the rush and the price jump.

Groceries

When to Buy: Sunday -- or Tuesday

Why: Maximize savings by combining store sales, which run from Wednesday to Tuesday, with the latest round of coupons from your Sunday paper, says Mary Hunt, publisher of Debt-Proof Living, a money-saving newsletter. "It's a smart idea to wait until you have those in hand to match up with the week's sale items," she says.

To snag savings on items you don't need just yet, shop on Tuesday, advises Hunt. Chances are, the store will have run out of the sale items. "That means you can pick up rain checks, which allow you to buy those items later when you need them, and at the sale price," she says.

Hotel Rooms

When to Buy: Sunday

Why: There are two kinds of hotel managers, and the kind that won't give you a discount on your room rate has Sundays off, says Greenberg. Call the hotel directly, and ask to speak with the manager on duty or the director of sales. These employees are open to negotiation, he says. They'd rather have a booked room at a discounted rate than an empty room. (The rest of the week, your call would get you a so-called revenue manager, who monitors profits -- and is rarely willing to lower rates.)