予定だった

was supposed to

→ 予定
phrase Uncommon #19,653
was supposed to Describes something that was planned or scheduled to happen in the past; it does not necessarily mean it failed to happen.
JA: 昨日は早く出発する予定だった。
EN: I was supposed to leave early yesterday.

私はその仕事を昨日終える予定だったが終えることができなかった。

I was supposed to finish that work yesterday, but I couldn't.

もともと夏休みの間だけの予定だったから

Because it was originally only supposed to be for summer break.

— When Marnie Was There (2014)

このバスに乗る予定だったけど、とても混んでいます。

I was planning to take this bus, but it's very crowded.

私は翌朝パリに向かう予定だった。

I was planning to head to Paris the next morning.

私はあと二日でフランスへと出発する予定だったので、荷造りに忙しかった。

I was busy packing because I was scheduled to leave for France in two days.

私達は夜にボストンを離れる予定だった。

We were planning to leave Boston at night.

二本マストの船は航海中で、一週間後には戻る予定だった。

The two-masted ship was at sea and was expected to return a week later.

トムとメアリーは植物園で会う予定だった。

Tom and Mary were supposed to meet at the botanical garden.

日曜日に出発する予定だったんだそこに着いたら結婚するつもりだった

I was planning to leave on Sunday. Once I got there, I was going to get married.

— ミスティック・リバー (2003)

カーバーの予定だったけど胃の調子が悪いみたい

I was planning to carve, but it seems my stomach is upset.

— ブレット・トレイン (2022)