How to make the Date format correct in Excel?


Right now I’m dealing with some Excel Data.

There’re some content about the Date the process read from the DataTable like 2020/4/15.
However, when I tried to append it back, the format will change to 2020/4/15 00:00:00.
Even the way I want it to be displayed as Date.ToString(“yyyy/MM/dd”)

How could I change its format?