5 Thursday is fine with me.
周四我有空。
I think I can find the time to visit your office tomorrow.
我想我明天能抽出时间去您的办公室拜访您。
Yes, I can meet you at that time because I will be free.
是的，那个时间我有空见你。

6 Two o'clock is not good for me.
两点钟我没空。
I'm afraid I have a prior commitment on the 20th.
恐怕我在20号已经有预约了。
I'm sorry but I can't make it by 5. How about an hour later?
很抱歉，五点钟我没空。一个小时后怎么样？
I'm sorry but I'll be occupied that week.
不好意思我下周都没空。