title: Assign inputted date to a variable
body: <p>I currently have an app that makes a request through an API call, and returns the data.  I created two date methods (the request uses these dates as parameters), so that it always calls the data from last week:  </p>
  
  <pre><code>def self.monday
    d = Date.today
    seven_days_ago = (d - 7)
    seven_days_ago.beginning_of_week
  end
  
  
  def self.sunday
    d = Date.today
    seven_days_ago = (d - 7)
    seven_days_ago.end_of_week
  end
  </code></pre>
  
  <p>I would like to use these monday and sunday methods as the default values for the application, but if the user inputs dates in a form, these methods will be overwritten by the inputted values.  These inputted values should stay as the user is navigating the site, until there is a new session, or they clear the values (thus sending the methods back to their default values).</p>
  
  <p>How would I create a form that doesn't save dates to a database, but just overwrites the default dates in the two methods above?  Then those dates should stay active until they clear that form, or they start a new session?</p>