中断 and 中止: an interruption and stopping an activity
Compare interrupted work with a decision to stop it, keeping the interruption separate from a confirmed restart time.
Breaking an activity’s progress
中断, read ちゅうだん, means interrupting something in progress. 停電で作業を中断しました。 says that work was interrupted by a power outage.
作業は中断していますが、再開時刻は未定です。 says that work is interrupted and the restart time is undecided. An interruption is not a confirmed restart.
Stopping a planned or ongoing activity
中止, read ちゅうし, means stopping a planned or ongoing activity. 安全を確認できず、作業を中止しました。 says that work was stopped because safety could not be confirmed.
When 中止 refers to this task, keep its scope to that task. It does not also cancel separate work on other dates or every activity at the location.
A separate decision after interruption
一度中断した作業を、後日中止しました。 says that work once interrupted was later stopped. Do not merge the two decisions into one moment.
An interruption does not guarantee that the activity will resume. Check later wording such as 再開する or 再開しない for the actual follow-up plan.
Is the restart time fixed in 作業は中断していますが、再開時刻は未定です。?
Show the answer and why
No. It explicitly identifies interrupted work and an undecided restart time.