good day还是well day

good day

释义：

日安（白天见面或分手时的招呼）

例句：

Did you have a good day?

你这一天过得顺利吗？

well day释义：

好一天

例句：

At South County school, doctors from all around town to Keep Well Day.

在南部县一所学校的健康日那天，城里的医生都来学校了。