diff --git a/scripts/backfill-events.py b/scripts/backfill-events.py
index 5b596ab..5200bc6 100644
--- a/scripts/backfill-events.py
+++ b/scripts/backfill-events.py
@@ -344,11 +344,18 @@ def find_pr_for_claim(
                 )
                 commit_date = date_out.strip() if date_out.strip() else None
                 if commit_date:
+                    # git %aI returns ISO 8601 with T-separator; prs.merged_at
+                    # uses SQLite's space-separator. Lexicographic comparison
+                    # fails across formats (space<T), so normalize commit_date
+                    # via datetime() before comparing. Without this, PRs merged
+                    # within the same calendar day but earlier than the commit
+                    # hour are silently excluded (caught by Ganymede review —
+                    # Shaga's #2025 was dropped in favor of later #2032).
                     row = conn.execute(
                         """SELECT number FROM prs
                            WHERE status='merged'
-                             AND merged_at >= ?
-                             AND merged_at <= datetime(?, '+24 hours')
+                             AND merged_at >= datetime(?)
+                             AND merged_at <= datetime(datetime(?), '+24 hours')
                              AND (branch LIKE 'leo/%' OR branch LIKE 'theseus/%'
                                   OR branch LIKE 'rio/%' OR branch LIKE 'astra/%'
                                   OR branch LIKE 'vida/%' OR branch LIKE 'clay/%')