In this task, you're given passages that contain mentions of a time duration related quesry and we are supposed to write answer to a question that involves event “frequency", which refers to how often an event is likely to be repeated. For example, "taking showers" typically occurs ~5 times a week, "going to saturday market" usually happens every few weeks/months, etc. 
 Note that a lot of the questions could have more than one correct answers. We only need a single most-likely answer. Please try to keep your "answer" as simple as possible. Concise and simple "answer" is preferred over those complex and verbose ones.  

[EX Q]: Sentence: The Council does not have executive powers but meets biannually to discuss issues of mutual importance. Similarly, the Parliamentary Assembly has no legislative powers but investigates and collects witness evidence from the public on matters of mutual concern to its members. Reports on its findings are presented to the Governments of Ireland and the United Kingdom. During the February 2008 meeting of the British–Irish Council, it was agreed to set up a standing secretariat that would serve as a permanent 'civil service' for the Council. Leading on from developments in the British–Irish Council, the chair of the British–Irish Inter-Parliamentary Assembly, Niall Blaney, has suggested that the body should shadow the British–Irish Council's work. 
Question: How often does the British-Irish Council meet?
[EX A]: biannually

[EX Q]: Sentence: Some clock-shift problems could be avoided by adjusting clocks continuously or at least more gradually—for example, Willett at first suggested weekly 20-minute transitions—but this would add complexity and has never been implemented. 
Question: Willett's first suggestion was to change clocks by 20 minutes how often?
[EX A]: weekly

[EX Q]: Sentence: There are also parks on two major islands in the river: Belle Isle and Brown's Island. Belle Isle, at various former times a Powhatan fishing village, colonial-era horse race track, and Civil War prison camp, is the larger of the two, and contains many bike trails as well as a small cliff that is used for rock climbing instruction. One can walk the island and still see many of the remains of the Civil War prison camp, such as an arms storage room and a gun emplacement that was used to quell prisoner riots. Brown's Island is a smaller island and a popular venue of a large number of free outdoor concerts and festivals in the spring and summer, such as the weekly Friday Cheers concert series or the James River Beer and Seafood Festival. 
Question: How often does Friday Cheers take place on Brown's Island?
[EX A]:
weekly