星期五 means "Friday" and is the standard Chinese term for the fifth day of the week. Chinese weekdays follow a simple numbering system: 星期 (week) plus a number from 一 (Monday) to 六 (Saturday), with Sunday being 星期天 or 星期日. For example, 今天是星期五 means "today is Friday."
我们星期五下午开会,别忘了。
Wǒmen xīngqīwǔ xiàwǔ kāihuì, bié wàng le.
We have a meeting Friday afternoon, don't forget.
星期五晚上你有空吗?一起吃饭吧。
Xīngqīwǔ wǎnshang nǐ yǒu kòng ma? Yīqǐ chīfàn ba.
Are you free Friday evening? Let's have dinner together.
报告的截止日期是这个星期五。
Bàogào de jiézhǐ rìqī shì zhège xīngqīwǔ.
The deadline for the report is this Friday.