--- a/backend/lib/tasks/sync_nico.rake
+++ b/backend/lib/tasks/sync_nico.rake
@@ -48,7 +48,8 @@ namespace :nico do
      post = Post.where('url REGEXP ?', "nicovideo\\.jp/watch/#{ Regexp.escape(code) }([^0-9]|$)")
                 .first
      title = datum['title']
      original_created_at = datum['uploaded_at'] && Time.iso8601(datum['uploaded_at'])
      original_created_at = datum['uploaded_at'] &&
          Time.strptime(datum['uploaded_at'], '%Y-%m-%d %H:%M:%S')
      original_created_from = original_created_at&.change(sec: 0)
      original_created_before = original_created_from&.+(1.minute)
      if post
--- a/backend/spec/tasks/nico_sync_spec.rb
+++ b/backend/spec/tasks/nico_sync_spec.rb
@@ -38,8 +38,8 @@ RSpec.describe "nico:sync" do
        'code' => 'sm9',
        'title' => 't',
        'tags' => ['AAA'],
        'uploaded_at' => '2026-01-01T12:34:56+09:00',
        'deleted_at' => '2026-01-31T00:00:00+09:00' }])
        'uploaded_at' => '2026-01-01 12:34:56',
        'deleted_at' => '2026-01-31 00:00:00' }])

    # 外部HTTPは今回「既存 post なので呼ばれない」はずだが、念のため塞ぐ
    allow(URI).to receive(:open).and_return(StringIO.new("<html></html>"))