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SOLD  sign in front of house
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It's long been conventional wisdom that the housing market slows in the fall, when children go back to school and colder weather keeps would-be buyers indoors.

Housing site RealtyTrac recently decided to test that long-held belief, crunching data on 32 million condo and single-family home sales over the past 15 years. The conclusion: It's true. And the slowest day of the sluggish fall-selling season is today, October 8.

Which makes it a great day to buy a house.

Buyers who closed their purchase on October 8 paid, on average, 10.8% less than what RealtyTrac estimated their homes were worth. The discount looms even larger when you consider that on some days during brisker selling periods, buyers paid premiums. The worst day to buy a home, according to RealtyTrac, is Jan. 19, when buyers typically paid a premium of 9.6%.

One big caveat: The data reflect dates on which home sales closed, not when sellers accepted offers from buyers. It typically takes several weeks from that point until a sale actually closes. So while it's more difficult to pinpoint the best precise best time to make an offer on a home, that day may be sometime in early to mid-September.

Still, seasonal swings might be at least one factor to consider if you are shopping for real estate. On a $200,000 house or condo, that 20.4 percentage-point swing in potential value would amount to more than $40,000.

"It makes a big difference," says RealtyTrac analyst Daren Blomquist. "If you have some flexibility, it pays to strategize."

One more thing to note: A slow housing market primarily benefits first-time buyers. Those who already own homes typically need to unload their old houses before they move into a new one. So whatever price advantage they gain as buyers, they're likely to also give up as sellers.

Still, if you thinking of buying a home soon, the results are worth paying attention to. Buyers tended to have the upper hand throughout October, with prices throughout the month clocking in at about 2.6% below average, the most of any month. Buyers also saw significant discounts in winter months, including December and February, before the market begins to pick up again in the spring.