per week; a week, during a particular week; in that week
週に何日学校に行ってるの？
How many days a week do you go to school?
私はテレビを週に二回見ます。
I watch TV twice a week.
彼は週に三回塾に行く。
He goes to cram school three times a week.
週に何冊か本を読みます。
I read several books a week.
週にいくらぐらい使う？
About how much do you spend a week?
彼は週に何日も働かないし、収入もほとんど無い。
He doesn't work many days a week, and he earns very little.
その雑誌は週に一回発行される。
That magazine is published once a week.
彼は前の週に日本に来ていたと言った。
He said he had come to Japan the week before.
彼はその週にパーティーを開きますので来てください、と言った。
He said he was having a party that week and asked me to come.
それはその前の週に買ったものでした。
It was something I had bought the week before.
勤務始めの週に制服をなくしたんですから安心しな
You lost your uniform during your first week on the job, so don’t worry.
— キャッチ・ミー・イフ・ユー・キャン (2002)