down time

noun

1. the time during which a machine, factory, etc. is shut down for repairs or the like
2. the time during which a computer or computer system is down, or inoperative, due to hardware or software failure
3. also written down time or down-time
   1. time spent not working; free or leisure time
   2. a brief period of inactivity occurring between tasks or obligations; rest, pause, break, etc.
   3. an unproductive period caused as by illness, unexpected difficulties, etc.