unavailable time; downtime
Technical computing term for the period when a system, service, or resource is not available for use.
We need to minimize the downtime of this system.
The server's unavailable time is from 2 a.m. to 4 a.m. every Sunday for maintenance.
ダウンタイム is a common loanword for 'downtime' in IT contexts, while 使用不能時間 is a more formal, kanji-based term often used in technical documentation.
Compound of 使用 (use), 不能 (impossible/unavailable), and 時間 (time). A straightforward technical term formed from standard Sino-Japanese elements.