延期 and 中止: postponing an event or canceling it
Read event notices accurately, distinguishing postponement from cancellation and checking whether a new date has been set.
Moving the planned time later
延期, read えんき, means postponement. 会議を来週に延期しました。 means that the meeting was postponed until next week.
会議は延期になりましたが、新しい日程は未定です。 says that the meeting was postponed but its new schedule is undecided. Postponement alone does not tell you the new date.
Stopping a planned or ongoing activity
中止, read ちゅうし, means canceling or stopping an activity. 雨のため、今日の試合は中止です。 says that today's match is canceled because of rain.
Canceling this match does not mean that no matches will ever be held. 中止 applies to the event or action identified in the notice.
Separating the reason from the new plan
台風のため、旅行を延期しました。 means that the trip was postponed because of a typhoon. 台風のため gives the reason; 延期しました states the response.
旅行を中止しました。 says that the trip was canceled. It does not rule out planning a separate trip later.
Has a new meeting date been finalized in 会議は延期になりましたが、新しい日程は未定です。?
Show the answer and why
No. The meeting has been postponed, and the new schedule is explicitly described as 未定, or undecided.