snippet.rb

  named_scope :since, lambda { |dateterm| 
    day = Chronic.parse(dateterm, :context => :past)
    day = Time.parse(dateterm) if day.nil?
    raise "Could not parse date" if day.nil?
    { :conditions => ['created_at >= ?',  Time.zone.parse(day.to_date.to_s).utc], :order => 'created_at asc' }
  }

  named_scope :on, lambda { |dateterm| 
    day = Chronic.parse(dateterm, :context => :past)
    day = Time.parse(dateterm) if day.nil?
    raise "Could not parse date" if day.nil?
    day = Time.zone.parse(day.to_date.to_s).utc
    { :conditions => ['created_at >= ? and created_at < ?',  day, day + 86400], :order => 'created_at desc' }  
  }