星期幾

星期几
xīng
which day of the week

CEDICT

which day of the week (question)

Wiktionary

Examples

你星期幾學漢語?

Which day do you learn Chinese?

Source: Tatoeba

我不知道他星期幾會來。

I don't know what day he'll come.

Source: Tatoeba

Entry Composition