Find elapsed time between two dates when change in cell value occurs

[jetpack]

Working with process temp controller, the data is formatted in a series as the following;

Start Hi T Lo T T SD ET
01/21/13 105.23 105.98 105.66
01/27/13 105.77 105.33 105.55 6 D .11 deg F

The need is to find lapsed time between when a higher temp was recorded since the temp when machine was shutdown(Temp SD)and the difference between the two temps. This may have occurred minutes, hours, or days since the last recorded temp. I am showing days elapsed just to make it simpler to visualize. The result will be stored in cell Elapsed Time (ET), for example on the row where the temp difference occurred as shown in the example.

Would prefer a cell formula if possible.

Any help greatly appreciated.

 

[jetpack]

Should have added that the need is to find the first time temp is higher than the temp at shutoff. This will need to be evaluated on an ongoing basis each time start up of machine occurs.