diff --git a/app/lib/data/repositories/remote_journal_repository.dart b/app/lib/data/repositories/remote_journal_repository.dart
index 4d7e9b4..c3a4e0f 100644
--- a/app/lib/data/repositories/remote_journal_repository.dart
+++ b/app/lib/data/repositories/remote_journal_repository.dart
@@ -21,8 +21,13 @@ class RemoteJournalRepository implements JournalRepository {
     int? pageSize,
   }) async {
     final queryParams = <String, dynamic>{};
-    if (dateFrom != null) queryParams['date_from'] = dateFrom.toIso8601String();
-    if (dateTo != null) queryParams['date_to'] = dateTo.toIso8601String();
+    // 后端 NaiveDateTime 格式: "2026-06-01T00:00:00"（不带毫秒）
+    if (dateFrom != null) {
+      queryParams['date_from'] = dateFrom.toIso8601String().replaceFirst(RegExp(r'\.\d+'), '');
+    }
+    if (dateTo != null) {
+      queryParams['date_to'] = dateTo.toIso8601String().replaceFirst(RegExp(r'\.\d+'), '');
+    }
     if (page != null) queryParams['page'] = page;
     if (pageSize != null) queryParams['page_size'] = pageSize;