diff --git a/NodeSrv/docs/superpowers/plans/2026-09-05-healthcheck-lineworks-survey-n8n.md b/NodeSrv/docs/superpowers/plans/2026-09-05-healthcheck-lineworks-survey-n8n.md
index 11ae4d1d..50b62f43 100644
--- a/NodeSrv/docs/superpowers/plans/2026-09-05-healthcheck-lineworks-survey-n8n.md
+++ b/NodeSrv/docs/superpowers/plans/2026-09-05-healthcheck-lineworks-survey-n8n.md
@@ -258,7 +258,7 @@ function tryParseEraDate(compact) {
     throw new Error("日付形式で回答してください（例: 令和6年3月1日）");
   }
 
-  return finalizeDateParts(ERA_INFO[era] + eraYear - 1, month, day);
+  return finalizeDateParts(ERA_INFO[era] + eraYear, month, day);
 }
 
 function tryParseMonthDay(compact) {