まだまとめ途中ですが、分かったところまで書きます。
I visited my aunt in Kyoto during the summer vacation.
夏休みに、という例文で見かけます。
Grammar Quizより引用
During indicates a period or range of time (having duration) and is used to say that something happened. “throughout this time” or “sometime within this time”. A clause with during focuses more on what happened—the activity, event or experience.
特定期間の前に。何が起こったかに焦点がある。
| ACTIVITY THROUGHOUT THIS PERIOD |
| We sat on the beach during the morning hours. |
| EVENT |
| The beach is fulll during Easter. |
| EXPERIENCE |
| We went to the sea often during our childhood. |
We spent time near the sea during our stay in Greece.
In specifies when an activity occurs/occurred, the timing of the activity—part of day, month, season, year. A clause wit in focuses more on when something happened than what happened. In may specify how soon or how long something takes/took. (See timelines in the next section.)
出来事がいつ起こったかを明らかにする。出来事よりも時、長さ、タイミングに焦点がある。
| HIS PERIOD |
| We sat on the beach in the morning. |
| DURATION—QUANTITY HOW LONG? |
| We swam a mile in an hour. (within an hour’s time, 60 minutes) |