The only thing constant is change, at least when it comes to real estate wisdom. For years, real estate website Zillow has said that the best time to list your home in Dallas-Fort Worth is May 1-15, but now it seems buyers are more ready to sign on the dotted line in midsummer.

July 1-15 is the new magic window, with DFW sellers earning a premium of $1,400 more (or 0.6 percent) and selling 2.5 days faster than the average listing throughout the year.

Nationally, early May still reigns among the 35 large markets analyzed, depositing $1,600 more into the pockets of sellers and selling a whole week faster.

Zillow found that before putting their homes on the market, sellers spend about seven months on average thinking about their decision. During that time, most sellers complete at least one home improvement project before listing, so knowing the best listing window gives them time to prepare their home.

"Sellers time their listings to optimize their sale in all sorts of ways," says Skylar Olsen, Zillow's director of economic research and outreach. "Some need to time the sale just right to manage their own synchronized home purchase. Others are seeking to get the highest sale price possible. Balancing these two common priorities suggests that an early May listing date is your best bet, but working with an agent who can weigh the local market and your unique priorities is still our lasting advice."

The rest of Texas is bucking the trend this year, too. Houston's timeframe and numbers are almost identical to DFW, though its homes sell a whole day quicker. In San Antonio, listing in early April will net you $1,200 more and move homes off the market a whopping 8.25 days faster.

Austin remains the most in line with the rest of the country, with May 16-31 being the best time to list. That will bring in an extra $1,400 and sell just a little over a week faster than the rest of the year.

Selling in early May remains the smartest decision for Minneapolis-St. Paul, where the premium tops out at 1.8 percent ($4,900) and is the highest among the cities studied.

One element that hasn't changed over the years is what day of the week is best to list — in every Texas market, the day that draws the most eyeballs to a new listing on Zillow remains Saturday.