Formula for working out top X of a date time difference

Good Afternoon,

I was wondering if someone could please assist me with an issue that I have?

Issue:
1. The attached file shows an example extract of a data extract that has thousands of lines. See the Data Tab.
2. What I need is some time that has passed between two dates in a DDHHMM format
3. What I then need is the top 50 of each of the times (or the longest time past)
4. The column headers will be: WO Number | Contractor Name | Time Calculation – see the various Report tabs
5. The calculations in the Data tab are between the following columns.
a. Difference between Column Z and Column AC
b. Difference between Column AC and Column AD
c. Difference between Column AD and Column AE
d. Difference between Column AE and Column AF
6. Is it possible to show the top 50 only in time?

This is a really tricky one and not sure it is possible easily but I sure hope so. This report is forming a part of a larger report and all other formulas are already present so I am hoping to keep the file size quite small. The aim is to then hand this over to someone else to just print on a monthly basis depending on the data that gets added with minimum input.

Thank you so much,
Andrew