The reason might surprise you.

Never Buy Wine on the Weekends
Credit: © Getty Images/fStop

When do you buy wine? If you hit the shop to stock up on Saturday or Sunday, you might want to rethink your habits. It turns out that wine is at its priciest on the weekend.

The mobile shopping app Ibotta, which doles out rebates on certain products to users based on their uploaded grocery receipts, has used those same receipts to analyze the ideal days to stock up on the vino. According to Delish, the app utilized the data from 50 million user-submitted receipts and found that when it comes to shopping for wine and beer, Saturdays and Sundays are the worst possible times, so it's best to stock up for your weekend drinking needs early.

On average, users saved 6 percent doing their booze buying on Tuesday, and 9 percent shopping on Monday—just in time for your Bachelorette watching party. While those savings might sound small, if you're taking home a couple of bottles a week or stocking up for a party, that excess cash quickly adds up. We recommend spending it on more wine.