down·time /ˈdaʊnˌtaɪm/
  停工期
  downtime
  當機時間; 損壞的時間
  downtime
  停機時間 當機時間
  downtime
       n : a period of time when something (as a machine or factory) is
           not operating (especially as a result of malfunctions)
           [ant: uptime]