A yearlong engagement is nice—but you might need more time than that to get the wedding date and site you want. Popular venues are already booking receptions for spring 2008 and beyond. The Hay-Adams hotel in downtown DC and the Chesapeake Bay Beach Club in Stevensville, Maryland, are negotiating for October 2008; DC’s Fairmont Hotel has a wedding scheduled for June 2009.

Still hoping to marry this year? As of early May, Georgetown’s Dumbarton House had 16 open Saturdays, particularly in late summer and winter, and the Mansion at Strathmore in North Bethesda had four. It’s possible to find a site—a bride whose fiancé is leaving for Iraq booked the Chesapeake Bay Beach Club six weeks before the wedding—but most places book about a year in advance.

Couples can expect a tougher time during prime wedding months—April through June and September through November—especially on holiday weekends. Several sites say fall is the busiest season for weddings, but even traditionally less popular dates go quickly—especially in winter, when venues might offer discounted rates or fill ballrooms with corporate holiday parties. Couples also compete with bar and bat mitzvahs on Saturday nights. Friday-night nuptials are becoming more popular. The Fairmont has booked a dozen this year.

Even if the date you want is open, consider other Washington events that could complicate plans. Marissa Hershon, special-events manager at the National Museum of Women in the Arts, recommends checking the Washington Convention Center calendar (www.dcconvention.com/events/default.asp) before set­ting a date. Some streets close and hotels fill up during IMF/World Bank meetings. The staff at Evermay and Halcyon House, both near Georgetown University, warn guests about traffic during graduation weekend.

Couples who are in law school or who have hectic work schedules often book the furthest in advance. Scott Button of the Westin Embassy Row in DC says one couple recently scheduled a wedding for July 2011: “At first I thought, ‘No, really—what’s the date?’ ”