I would like to calculate the difference in number of days between 2 dates based on unique ID's.
Here is a sample of my date:
ID Interview Date Interview Date Planned Number of Days
ID 1 Interview 1 01/05/2017 15/04/2017
ID 1 Interview 2 05/05/2017 15/04/2017
ID 1 Interview 3 12/05/2017 15/04/2017 ??
ID 2 Interview 1 10/04/2017 13/03/2017
ID 2 Interview 2 15/04/2017 13/03/2017 ??
In the fields marked by question marks I would like to see the difference between the latest 'Date Interview' and 'Date Planned' for ID 1 and ID 2 and all other ID's I have in my file.
In my example we can clearly see that '12/05/2017' is the latest date for ID 1 but can I make it so that in the column 'Number of Days' I get the difference in days between the latest 'Date Interview' and 'Date Planned' for the respective ID ?