While “这周” is a simple time expression, its use reveals a key cultural difference in how the week is structured.
In modern China, as in most of the world, the work and school week follows the seven-day Gregorian calendar. However, the crucial difference is that the week officially and culturally begins on Monday, not Sunday.
Chinese System:
Monday is 星期一 (xīngqī yī) - “Week Day One”
Tuesday is 星期二 (xīngqī èr) - “Week Day Two”
…and so on, until Sunday, which is 星期天 (xīngqī tiān, “week day sky”) or 星期日 (xīngqī rì, “week day sun”).
Comparison to Western System: In many Western countries, particularly the United States, calendars often display Sunday as the first day of the week, even though the “work week” begins on Monday. This can lead to scheduling confusion. If a Chinese friend says “let's meet on the first day of this week (这周第一天),” they mean Monday. This numerical, logical system for naming the days is highly practical and reflects a straightforward approach to timekeeping in modern China.