diff --git a/tools/backfill-issue-timestamps.sql b/tools/backfill-issue-timestamps.sql
new file mode 100644
index 0000000..0cc84a8
--- /dev/null
+++ b/tools/backfill-issue-timestamps.sql
@@ -0,0 +1,90 @@
+-- Copyright 2016 The Chromium Authors. All Rights Reserved.
+--
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file or at
+-- https://developers.google.com/open-source/licenses/bsd
+
+
+DROP PROCEDURE IF EXISTS BackfillIssueTimestampsChunk;
+DROP PROCEDURE IF EXISTS BackfillIssueTimestampsManyChunks;
+
+delimiter //
+
+CREATE PROCEDURE BackfillIssueTimestampsChunk(
+    IN in_pid SMALLINT UNSIGNED, IN in_chunk_size SMALLINT UNSIGNED)
+BEGIN
+
+  DECLARE done INT DEFAULT FALSE;
+
+  DECLARE c_issue_id INT;
+
+  DECLARE curs CURSOR FOR
+    SELECT id FROM Issue
+    WHERE project_id=in_pid
+    AND (owner_modified = 0 OR owner_modified IS NULL)
+    AND (status_modified = 0 OR status_modified IS NULL)
+    AND (component_modified = 0 OR component_modified IS NULL)
+    LIMIT in_chunk_size;
+
+  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
+  OPEN curs;
+
+  issue_loop: LOOP
+    FETCH curs INTO c_issue_id;
+    IF done THEN
+      LEAVE issue_loop;
+    END IF;
+
+    -- Indicate progress.
+    SELECT c_issue_id AS 'Processing:';
+
+    -- Set the fields to the largest timestamp of any relevant update.
+    UPDATE Issue 
+    SET 
+    owner_modified     = (SELECT MAX(created)
+                          FROM IssueUpdate
+                          JOIN Comment ON IssueUpdate.comment_id = Comment.id
+                          WHERE field = 'owner'
+                          AND IssueUpdate.issue_id = c_issue_id),
+    status_modified    = (SELECT MAX(created)
+                          FROM IssueUpdate
+                          JOIN Comment ON IssueUpdate.comment_id = Comment.id
+                          WHERE field = 'status'
+                          AND IssueUpdate.issue_id = c_issue_id),
+    component_modified = (SELECT MAX(created)
+                          FROM IssueUpdate
+                          JOIN Comment ON IssueUpdate.comment_id = Comment.id
+                          WHERE field = 'component'
+                          AND IssueUpdate.issue_id = c_issue_id)
+    WHERE id = c_issue_id;
+
+    -- If no update was found, use the issue opened timestamp.
+    UPDATE Issue SET owner_modified = opened
+    WHERE id = c_issue_id AND owner_modified IS NULL;
+
+    UPDATE Issue SET status_modified = opened
+    WHERE id = c_issue_id AND status_modified IS NULL;
+
+    UPDATE Issue SET component_modified = opened
+    WHERE id = c_issue_id AND component_modified IS NULL;
+
+  END LOOP;
+
+  CLOSE curs;
+END;
+
+CREATE PROCEDURE BackfillIssueTimestampsManyChunks(
+    IN in_pid SMALLINT UNSIGNED, IN in_num_chunks SMALLINT UNSIGNED)
+BEGIN
+  WHILE in_num_chunks > 0 DO
+    CALL BackfillIssueTimestampsChunk(in_pid, 1000);
+    SET in_num_chunks = in_num_chunks - 1;
+  END WHILE;
+END;
+
+
+//
+
+
+delimiter ;
+