average length of an engagement

The department store chain is stepping up its nuptials game in the hopes of winning a bigger slice of the $60 billion U.S. wedding pie. Among other moves: Macy's is adding higher-end bridal jewelry to its assortment and training its army of personal shoppers to advise anxious couples.
While Macy's has long served people who are getting hitched, its offerings have traditionally revolved around gift registries. Macy's has typically become part of the average couple's planning eight months into the process, meaning it has been missing out on chances to sell items earlier, like the engagement ring or even a skin care and weight-loss regimen as the bride and groom prepare for their big day. Yet the average length of an engagement in the United States is 14.5 months, according to a 2015 survey of 18,000 brides by The Knot, a leading wedding marketplace.
"We have an opportunity to service the couple throughout the entire wedding journey, not just at the point of registry," Shawn Outler, the Macy's senior vice president overseeing the wedding strategy, told Fortune on a tour of the retailer's Manhattan flagship. "We weren't quite messaging to those opportunities but we knew we were selling the product."

http://fortune.com/2016/05/06/macys-weddings/