* Missing files

* Work on post exploration code by traversing dates

app/logical/date_tag.rb

@@ -0,0 +1,72 @@
+class DateTag
+  attr_accessor :tag, :start_date, :end_date
+  
+  def self.new_from_range(start, stop)
+    new("#{start.to_formatted_s(:db)}..#{stop.to_formatted_s(:db)}")
+  end
+  
+  def initialize(tag)
+    @tag = tag
+  end
+  
+  def is_single_day?
+    tag =~ /^\d+-\d+-\d+$/
+  end
+  
+  def is_range?
+    !is_single_day
+  end
+  
+  def start_date
+    return date if is_single_day?
+    extract_ranges
+    start_date
+  end
+  
+  def end_date
+    return date if is_single_day?
+    extract_ranges
+    end_date
+  end
+  
+  def previous_week
+    DateTag.new_from_range(1.week.ago(start_date), 1.week.ago(end_date))
+  end
+  
+  def next_week
+    DateTag.new_from_range(1.week.since(start_date)), 1.week.since(end_date)
+  end
+  
+  def previous_month
+    DateTag.new_from_range(1.month.ago(start_date), 1.month.ago(end_date))
+  end
+  
+  def next_month
+    DateTag.new_from_range(1.month.since(start_date)), 1.month.since(end_date)
+  end
+  
+  def date
+    Date.parse(tag)
+  end
+  
+  private
+    def extract_ranges
+      case tag
+      when /\A(.+?)\.\.(.+)/
+        self.start_date = Date.parse($1)
+        self.end_date = Date.parse($2)
+
+      when /\A<(.+)/, /\A<=(.+)/, /\A\.\.(.+)/
+        self.start_date = 20.years.ago
+        self.end_date = Date.parse($1)
+
+      when /\A>(.+)/, /\A>=(.+)/, /\A(.+)\.\.\Z/
+        self.start_date = Date.parse($1)
+        self.end_date = Date.today
+
+      else
+        self.start_date = Date.today
+        self.end_date = Date.today
+      end
+    end
+end

app/logical/post_set.rb

@@ -43,6 +43,10 @@ class PostSet
     tag_array.size == 1
   end
   
+  def date_tag
+    tag_array.grep(/date:/).first
+  end
+  
   def load_associations
     if is_single_tag?
       @wiki_page = WikiPage.find_by_title(tags)