scheduled maintenance
Primarily used in computing and engineering for planned, periodic maintenance of systems, equipment, or software.
サーバーの定期保守は毎週日曜日の深夜に行われます。
Scheduled maintenance of the server is performed late every Sunday night.
定期保守のお知らせが届いた。
A notice of scheduled maintenance arrived.
Compound of 定期 (periodic) and 保守 (maintenance). A straightforward Sino-Japanese technical term.