I have created a calculated column named TimeInProgress that will show the final calculated value based on the formula. I have also added another Boolean(Yes/No) field named Contact Signed . If Contract Signed is YES the TimeInProgress value will be blank. Only if it is not signed(value= No), the calculated column will be populated. The formula used is :
=IF([Contract Signed],"",DATEDIF(Created,TODAY(),"d"))
Output :
Calculated Column Formula :
In case you want to show some text in the calculated column other than leaving it blank, you can update the formula as
=IF([Contract Signed],"SomeText",DATEDIF(Created,TODAY(),"d"))