星期
week
xīngqī
What does 星期 mean?
星期 (xīngqī) means 'week,' and it is also the root for naming days of the week: 星期一 'Monday,' 星期二 'Tuesday,' through 星期六 'Saturday,' with 星期天 (xīngqī tiān) or 星期日 (xīngqī rì) for 'Sunday.' To ask 'what day is it?' use 今天星期几? (jīntiān xīngqī jǐ). To count weeks, add a measure word: 一个星期 'one week,' 两个星期 'two weeks.' The synonym 周 (zhōu) means the same thing and is more common in written or formal contexts: 周一 'Monday' (written), 周末 'weekend.' Both 星期 and 周 are correct; 星期 is the textbook HSK 1 form and what learners are usually taught first. Note 星期 literally means 'star period,' a calque from Buddhist astronomy.
Character breakdown
star
period; phase
Memory hook: 星期 = 'star period.' Each day in the old astronomical week was named for a star — Mandarin kept the name but numbered the days.
Measure word for 星期
Example sentences
今天星期几？
Jīntiān xīngqī jǐ?
What day of the week is it today?
spoken
今天星期三。
Jīntiān xīngqī sān.
Today is Wednesday.
neutral
我下个星期去上海。
Wǒ xià ge xīngqī qù Shànghǎi.
I'm going to Shanghai next week.
neutral
一个星期有七天。
Yí ge xīngqī yǒu qī tiān.
A week has seven days.
neutral
Common phrases with 星期
Synonyms
周 means 'week' too, but it's shorter and more written/formal. 周一 = 星期一 'Monday.' Calendars, news, and offices use 周; spoken Chinese and HSK 1 textbooks use 星期.
Colloquial, common in southern China and Taiwan: 礼拜一 'Monday.' Originally a Christian term ('worship day'). Northern Mandarin speakers prefer 星期 or 周.
Don't confuse 星期 with
周末 specifically means 'weekend' (Saturday and Sunday). 星期 is the full week. 周末你做什么? = 'What are you doing on the weekend?'
星 alone means 'star.' 星期 is a fixed compound — you can't drop 期 and still mean 'week.'