Question: How long is the Munich Germany festival where Hofbräu-Festzelt is one of the largest beer tents?

Context paragraphs:
Beer hall: A beer hall (German: "Bierpalast, Bierstube" ) is a large pub that specializes in beer.  Bavaria's capital Munich is the city most associated with beer halls; almost every brewery in Munich operates a beer hall.  The largest beer hall was the 5,000-seat Mathäser near the München Hauptbahnhof (Munich central train station), which has since been converted into a movie theater.

Northalsted Market Days: Northalsted Market Days is an annual two-day festival in Chicago, Illinois, United States.  It is the Midwest's largest street festival with annual attendance exceeding 300,000 people over the two-day event, takes place in the Boystown section of Lakeview along North Halsted Street from Belmont Avenue to Addison Avenue and is a half-mile long.  The festival consists of 3 music stages, 2 local band stages and a dance floor.  The festival showcases food and merchandise tents.  There are also Halsted business establishment tents, as well as those of radio stations, public service organizations & companies (SAAB in 2008).  Many give away small souvenir items.

Oktoberfest tents: There are a series of tents (often called "beer tents") at the Oktoberfest, which are operated by different Wiesn-hosts and in which some come from a long tradition.  Some tents belong to the local breweries.  The set up work for the tents often begins three months before the start of the festival.

Toronto's Festival of Beer: The Toronto Festival of Beer (TFOB), also known as Beerfest, is an annual event that takes place at Exhibition Place in Toronto, Ontario, Canada.  The festival celebrates Canada’s rich brewing history by featuring more than 120 brands around the world and many Ontario craft brewers.  The event has become Canada’s largest beer festival with 30,000 people attending every year.  Established in 1994, the Toronto Festival of Beer has been sampling beer for those ages 19+ for 17 years.

Joseph Schlitz Brewing Company: The Joseph Schlitz Brewing Company was an American brewery based in Milwaukee, Wisconsin, and once the largest producer of beer in the United States.  Its namesake beer, Schlitz ( ), was known as "The beer that made Milwaukee famous" and was advertised with the slogan "When you're out of Schlitz, you're out of beer".  Schlitz first became the largest beer producer in the US in 1902 and enjoyed that status at several points during the first half of the 20th century, exchanging the title with Anheuser-Busch multiple times during the 1950s.

Oktoberfest: Oktoberfest (] ) is the world's largest Volksfest (beer festival and travelling funfair).  Held annually in Munich, Bavaria, Germany, it is a 16- to 18-day folk festival running from mid or late September to the first weekend in October, with more than 6 million people from around the world attending the event every year.  Locally, it is often called the Wiesn, after the colloquial name for the fairgrounds, Theresa's meadows ("Theresienwiese").  The Oktoberfest is an important part of Bavarian culture, having been held since the year 1810.  Other cities across the world also hold Oktoberfest celebrations that are modelled after the original Munich event.

Hofbräu-Festzelt: The Hofbräu-Festzelt is one of the largest beer tents of the Oktoberfest in Munich, Germany.

Blue Mountain Brewery: The Blue Mountain Brewery in Afton, Virginia is a brewery which forms, along with Starr Hill Brewery, South Street Brewery, Wild Wolf Brewing Company and Devils Backbone Brewing Company, an integral part of the Brew Ridge Trail.  Blue Mountain was the first brewery to open in Nelson County.  They cultivate 1/3 acre of mainly Cascade-variety hops.  One of their seasonal beers, Blue Reserve, took home the first-ever medal (Silver) for a beer hopped solely with Virginia hops at the world's largest beer competition, the Great American Beer Festival, in 2011 for the American-Belgo Ale category.  Blue Mountain is also the only Virginia brewery to hold back-to-back Gold medals at the 2010 and 2011 Great American Beer Festival.  In 2012, a new sister brewery, Blue Mountain Barrel House, was opened by two of the founders of the original Blue Mountain Brewery.

Bürgerbräukeller: The Bürgerbräukeller was a large beer hall located in Munich, Germany.  Opened in 1885, it was one of the largest beer halls of the Bürgerliches Brauhaus company, a 19th-century brewery.  After Bürgerliches merged with Löwenbräu in 1921, the hall was transferred to that company.

Philly Beer Week: Philly Beer Week is a series of beer events held over a 10-day period in Philadelphia and the Delaware Valley area organized and operated by Philly Beer Week Inc., originating in 2007.  Events include festivals, dinners, tours, pub crawls, tastings and meet-the-brewer nights to area bars, restaurants and other locations throughout the city and surrounding suburbs hosted by over 200 area restaurants, breweries and beer stores.  Philly Beer Week is the largest beer celebration in the United States, and its successful model has been copied by over 100 other cities worldwide.

Supporting paragraphs: Hofbräu-Festzelt Oktoberfest
Answer: 16- to 18-day