It’s the moment we’ve all been waiting for. Today, the longest ever Amazon Prime Day begins. From Monday, July 16 through Tuesday, July 17, deals will be widespread across the site. But while deal days are an opportunity for consumers to snag items at low prices, they can also be a trigger for over-shopping.

Since the first Amazon Prime Day in 2015, the event has expanded from deals on the site to extra discounts for Prime shoppers who download the app, use Amazon Assistant, find items using camera search or shop at Whole Foods with an Amazon Prime Rewards Visa, according to Amazon’s website.

Amazon’s Echo Dot, an instant pot pressure cooker, 23andMe DNA tests, a plush seahorse and whey protein were some of the top items purchased around the world on Prime Day last year. The sales brought in nearly $3 billion to the e-commerce giant, and broke both its Black Friday and Cyber Monday records.

But for those who are always on the hunt for the best deal, Amazon Prime Day might not be a one stop shop.

When shopping, look at the price of the item, not what is listed as the discount.

“Don’t assume that because it’s on sale that it’s the lowest price of the year,” said David Dritsas, contributing editor at Brad’s Deals, a site dedicated to finding the best deals for a wide range of products on the internet.

Dritsas said to be wary of huge discounts. Something that is listed as 80 percent off, for example, might be 80 percent off the original price, not the price the item usually sells for on Amazon.

Consumers should also look to the competition for price comparisons, Dritsas said. Since Amazon created Prime Day, many other retailers have also jumped on the deal day trend.

“We find a ton of other deals that are better at other retailers,” Dritsas said.

For some items, like electronics, shoppers should also realize that July is not the time of year when the lowest prices are traditionally offered, Dritsas said. Christmastime generally has the best deals on televisions and laptops, so if you don’t need one right away, it may be best to wait.

“Buying something you don’t need isn’t saving money,” said Ryan Hudson, co-founder of Honey, a web browser extension that searches for the best online deals and coupons.

That’s one of the benefits of using an application like Honey to do research, Hudson explained. The chrome extension allows shoppers to look at price history charts for items they’re shopping for to assess if the deal they see is a good one.

“It’s important to give consumers that information,” Hudson said, so they don’t “just respond to what looks to be a ‘too good to be true’ one-time offer.”

If you are prone to impulse buys, April Benson, PhD, the author of “To Buy or Not to Buy: Why We Overshop and How to Stop” says to ask yourself these six questions.

1. Why am I here?

2. How do I feel?

3. Do I need this?

4. What if I wait?

5. How will I pay for it?

6. Where will I put it?

“If they can answer these six questions satisfactorily to themselves, then it is probably not an impulse purchase,” said Benson.

Benson also says that overshoppers should write down everything they spend money on and assign it a score, limit the amount of time they spend online and take their credit card information off of sites like Amazon.

“It gives more time to pause,” said Benson.

Another thing to be wary of is the offer of extra deals or discounts if you sign up for a rewards credit card.

“A lot of people will be tempted to sign up for an Amazon credit card,” said Jeanette Pavini, a savings expert at Coupons.com. “It’s just not always the best move.”

Signing up for a new card opens another inquiry on your credit, Pavini said, which can be detrimental especially if you’re trying to buy a house, car or trying to get approved for a loan.

To make the best of deal days, have a plan, said Pavini.

One thing that is tricky with Amazon Prime Day is that not all of the prices of sale items are available beforehand. Still, Pavini says this is a good opportunity to do research and find out base prices of items you’d like to purchase to compare to Amazon’s price.

Even on Amazon, Pavini said to look out for free shipping and make sure that you know the return policy. Some places may charge a restocking fee, especially for returned electronics, she said.

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Pavini also said to look out for new offers, like the week of deals at Whole Foods for Prime Day this year. Prime members will also get a $10 credit for $10 spent at Whole Foods between July 11 and July 17, according to the press release from Amazon.

“That’s a unique little perk this year,” Pavini said.

If you see something that you want and you know it’s at a good price, try to buy it as soon as possible, said Dritsas from Brad’s Deals.

“It could go within minutes,” said Dritsas. It you’re in the market for something specific, he said to set up price alerts or reminders for the item.

In addition, Dritsas said to look at the deals that Amazon is offering on subscription services, like Amazon music. Many are being offered for low prices and rarely go on sale at any other time of year. The deals are also offered longer than the 36-hour Prime Day blitz, Dritsas said.

Just remember that after the trial period ends, you will be charged full price for the services, said Dritsas. If you aren’t willing to pay that price, make sure that you remember to cancel the subscription, he said.

Overall, the most important thing for your wallet and shopping budget is to not get carried away in the excitement of the day and a half.

“The bottom line — you can never get enough of what you don’t really need,” Benson said.