A week — a seven-day period used as a unit of time (used for schedules, durations, etc.).
来週の金曜日は休みなので、週末は旅行に行きます。
Next Friday is a holiday, so I will go on a trip over the weekend.
この本は一週間で読み終えた。
I finished reading this book in a week.
彼は週に三回ジムに行く。
He goes to the gym three times a week.
週の初めに予定を確認しましょう。
Let's check the schedule at the start of the week.