Subtracting dates

I've got a table (5 columns) with a list of dates. I want to subtract the dates in each column. I've no problem with subtracting the dates per se, however here's the problem.

I need to subtract them in ascending order i.e the largest minus the 2nd largest, the 2nd largest minus the 3rd largest etc. However there is no order of the dates across the 5 columns. I.e on some rows, the largest will be in column 3, on others it will be in column 1.

Any ideas?

I've attached a file with the typical table on the LH side. On the RH side is what I need to get out of it, however I had to create this manually. I've got a very big list so I need a formula, macro that can do it for me.

Help gratefully received!