How do I create a new column that sum the delta between to dates which are in different column?

[#1]

How do I create a new column that sum the delta between to dates which are in different column?

This is my data table:

Name	Start	End1	End2	Delta between Start and End (minutes)
aaa	3/2/2020 21:51	3/2/2020 22:59		68
bbb	3/1/2020 18:12		3/1/2020 19:00	48

[#2]

Assuming the Start and End1 columns are true JMP date/time columns, all that has to be done is to use the formula
:End1 - :Start
and then set the format for the new column to one of the Duration formats

[#3]

Thanks for your reply. 
I have several columns for "Start Date" and I want all the deltas to appear in one column.

once it will take the ":End1 - :Start" and once ":End2 - :Start".

How can I do that?

[#4 · Accepted solution]

My suggestion is to first stack the columns and then create the delta column
Tables=>Stack