Show blank in cell if

[Ed_Cooper]

I have a formula field that calculates the difference between {End date} and {Start date}.

Works fine
If there is no Start Date or no End date I want the cell to be blank instead of NaN
Been trying everything.
HELP!!

[Ed_Cooper]

[Kamille_Parks]

IF(
   AND({End Date}, {Start date}),
   DATETIME_DIFF({End Date}, {Start date}, "days")
)

[Ed_Cooper]

Perfect!
Thank you.
Appreciated.