during を使用して、何かがいつ起こるかを言います。何かが続く時間の長さについて話すために for を使います。

She phoned me during the week to tell me that she was getting married. （週のある時点を指す）

We were in the cinema for three and a half hours.

ない: … during three and a half hours .

Our flight to New York was delayed for seven hours.

ではない: … during seven hours .

We went to Italy for a week.

ない: … during a week .

祝日や季節を表すために for を使用することもできます。

He always goes to his mother’s house for New Year.

ではない: … during New Year 。