How to stop formula/calculations based on a text entry

Hi,

I have an issued with a spreadsheet I am currently working on that is based around staffing/manning lists.

The premise is, that each employee that starts with the company is added to the sheet which trackers a variety of things including their length of service which is displayed as attached in the image)


Then in cell CR there is a column titled "Leave Date".

The issue I'm having is I need the columns DAYS / WEEKS / MONTHS / YEARS to stop calculating when a date is entered in the Leave Data column

The current formula I have for these columns is as follows;

Days: =DATEDIF(G2,F2,"D")
Weeks: =DATEDIF(G2,F2,"D")/7
Months: =DATEDIF(G2,F2,"M")
Years = =DATEDIF(G2,F2,"Y")

Any help is much appreciated.

Regards

James

example.jpg