Calculate elapsed time between rows

[Anonymous]

I have a date/time column in my table.  I want a new column that will calculate the elapsed time in minutes between rows.  For example, the first row in the new column based on data in the screenshot below would be 30.  Row 2 would be 23.  Row 3 would be 7.  

How do I do this?  With DAX by adding a new column in the Excel data model?  Or by adding a Custom Column in Query Editor?  Either/or, I'd need the specific formula/statement spelled out for me to make it work.  

Any help would be appreciated.  

[Stachu · Accepted solution]

you can use advice from @ImkeF  on how to reference previous row in M
https://www.thebiccountant.com/2018/07/12/fast-and-easy-way-to-reference-previous-or-next-rows-in-po...

then you can just subtract one column from another, set its type to duration and remove the previous date column