周一 + Verb / 在 + 周一
周一 (zhōuyī) means "Monday" and is one of the standard ways to express days of the week in Chinese. The 周 (week) prefix followed by a number from one to six covers Monday through Saturday, while Sunday is 周日. For example, 周一开会 means "to have a meeting on Monday."
周一上午我有一个会议。
Zhōuyī shàngwǔ wǒ yǒu yī gè huìyì.
I have a meeting on Monday morning.
这个课程每周一和周三上。
Zhège kèchéng měi zhōuyī hé zhōusān shàng.
This course is held every Monday and Wednesday.
我们周一再讨论这件事吧。
Wǒmen zhōuyī zài tǎolùn zhè jiàn shì ba.
Let's discuss this matter again on Monday.