weeknote_week.rb

  # From: http://www.mcqn.com/cgi-bin/weeknotecalc
  def weeknote_week(this_week)
    registration_date = Date.civil(2010,3,29)

    # Get the start of the week for each of those dates
    if registration_date.wday == 0
      # wday of 0 is Sunday, and we want our weeks to start on Monday
      registration_date = registration_date - 6
    else
      registration_date = registration_date - (registration_date.wday - 1)
    end

    if this_week.wday == 0
      this_week = this_week - 6
    else
      this_week = this_week - (this_week.wday - 1)
    end
    week_number = (((this_week - registration_date)/7)+1).to_s
  end