diff --git a/app/constants/relation_types.rb b/app/constants/relation_types.rb
index 422c523..8ea85bd 100644
--- a/app/constants/relation_types.rb
+++ b/app/constants/relation_types.rb
@@ -68,4 +68,8 @@ module RelationTypes
     "datacite-crossref",
     "crossref",
   ].freeze
+
+  # relation_type_ids that affect counts in lupo.
+  SOURCE_RELATION_TYPES = ["references", "parts", "versions"].freeze
+  TARGET_RELATION_TYPES = ["views", "downloads", "citations", "part_of", "version_of"].freeze
 end
diff --git a/app/models/event.rb b/app/models/event.rb
index f65cece..0b06527 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -139,4 +139,32 @@ def obj_hash
     indexes :citation_year, type: :integer
     indexes :cache_key, type: :keyword
   end
+
+  class << self
+    def reindex_touched_dois(start_date:, end_date:, threads: 10)
+      total = 0
+
+      start_date.to_date.upto(end_date.to_date) do |date|
+        dois = Set.new
+
+        where(updated_at: date.all_day)
+          .where(source_relation_type_id: RelationTypes::SOURCE_RELATION_TYPES)
+          .distinct.pluck(:source_doi)
+          .each { |doi| dois << doi }
+        where(updated_at: date.all_day)
+          .where(target_relation_type_id: RelationTypes::TARGET_RELATION_TYPES)
+          .distinct.pluck(:target_doi)
+          .each { |doi| dois << doi }
+
+        # Test performance before enabling SQS queues.
+        # Parallel.each(dois.to_a, in_threads: threads) do |doi|
+        #   SqsUtilities.send_events_doi_index_message(doi)
+        # end
+
+        total += dois.size
+      end
+
+      total
+    end
+  end
 end
diff --git a/app/utilities/sqs_utilities.rb b/app/utilities/sqs_utilities.rb
index ddfe12b..aebfe83 100644
--- a/app/utilities/sqs_utilities.rb
+++ b/app/utilities/sqs_utilities.rb
@@ -6,6 +6,10 @@ def send_events_other_doi_job_message(data)
       send_message(data, shoryuken_class: "OtherDoiJob", queue_name: "events_other_doi_job")
     end
 
+    def send_events_doi_index_message(data)
+      send_message(data, shoryuken_class: "ReindexByDoiJob", queue_name: "lupo_background")
+    end
+
     private
 
     def send_message(body, options = {})
diff --git a/lib/tasks/event.rake b/lib/tasks/event.rake
index 8267c0f..04b1cd2 100644
--- a/lib/tasks/event.rake
+++ b/lib/tasks/event.rake
@@ -34,4 +34,22 @@ namespace :event do
 
     puts("Rake task has completed!")
   end
+
+  desc "Re-queue SQS re-index messages for unique DOIs in events updated within a date range"
+  # Dates are inclusive. END_DATE defaults to START_DATE for single-day runs.
+  task reindex_touched_dois: :environment do
+    raise "START_DATE is required" if ENV["START_DATE"].blank?
+
+    start_date = Date.parse(ENV["START_DATE"])
+    end_date   = Date.parse(ENV["END_DATE"].presence || ENV["START_DATE"])
+
+    raise "END_DATE must be on or after START_DATE" if end_date < start_date
+
+    count = Event.reindex_touched_dois(
+      start_date: start_date,
+      end_date:   end_date,
+    )
+
+    puts "Sent #{count} unique DOIs for re-indexing."
+  end
 end