create scopes for selecting LOs by created less than a week and a month ago

app/models/learning_object.rb

@@ -55,6 +55,8 @@ class LearningObject < ActiveRecord::Base
 
   default_scope { includes(:object_type, :attachment, :attachments).order(score: :desc) }
   scope :missing_thumbnail, ->() { where(thumbnail_file_name: nil) }
+  scope :this_week, -> { where('created_at >= ?', 1.week.ago) }
+  scope :this_month, -> { where('created_at >= ?', 1.month.ago) }
 
   searchkick language: 'brazilian', match: :word_start, searchable: [:name, :description, :author, :object_type], callbacks: :async