Hiya Experts!

I'm sure this one will be pretty straight forward but instead of banging my head on the wall I am posting here in the hope that a kind soul will give me a swift answer

Issue:
I am importing data from MS Project in MS Excel.

When doing so my Start and End dates arrive in the following state:
01/12/2008 09:00:00

Nice enough for MS Project but I am not precious about the hours on this particular project and would like not to have in Excel.

So I thought of doing this: =left(CELL,10)... which gave me: 39783,375

I tried to reformat it not no avail...

Question:
What do I need to do in order to remove the time short of manually going to each and every cell and deleting it?

Many thanks!!!