Learn how to simply calculate duration when you have only one date / time column.
In this video I quickly show you how to create a duration column using 1 single date / time column. This comes in handy when wanting to calculate differences in time period values stored in the same column.
To expand a little - if you want this to be responsive (say you have multiple sensors and want the duration to be dynamic with selections in sensors), that would also be possible using the "Interval" and "Above" chart functions- an expression like: