There was supposed to be a 〇〇 today but it was postponed.
A 〇〇 that was supposed to happen today was postponed.
ご質問ありがとうございます。
・「There was supposed to be a 〇〇 today but it was postponed.」
「A 〇〇 that was supposed to happen today was postponed.」
＝今日開催される予定だった〇〇（試合）は延期されました。
（例文）There was supposed to be a baseball game today but it was postponed.// That's too bad!
（訳）今日開催される予定だった野球の試合は延期されました。//それは残念ですね！
（例文）A boxing match that was supposed to happen today was postponed.
（訳）今日開催される予定だったボクシングの試合は延期されました。
※〇〇＝試合
野球の試合＝baseball game
サッカーの試合=soccer game
ボクシングの試合=a boxing match
・延期は「postpone」です。
（例文）They postponed the event due to Covid-19.
（訳）コロナの影響でイベントが延期になりました。
お役に立てれば嬉しいです。
Coco
This match was supposed to be held today, but it’s been postponed.
This match was supposed to be held today, but it’s been postponed.
The match was scheduled for today, but it got postponed.
This match was meant to happen today, but it’s been pushed back.
「今日開催される予定だった」は、英語だと was scheduled for today / was supposed to be held today が自然です。
・scheduled：スケジュール上「予定されていた」
・supposed to：本来そうなるはずだった（予定＋期待）
どちらも日常でもスポーツでもよく使います。
日本 
アメリカ合衆国 
