Converting datenums to get time durations

I need the time durations that the component is in operation, above a certain height. The time is in 24 hour time. So essentially I want to end up with a matrix with one column that has the component ID and another column with time durations for each component. Any advice?

% Load excel
data=xlsread('file.xlsm');
%%
CompID = data(:,1);
Date = data(:,8);
Height = data(:,10)
%% Converting datenum to datetime 
Date = datetime(Date,'ConvertFrom','yyyymmddHHSS');
%%
H = 3;
i = WaveHeight>H;
ThreshH = Height(i);
ThreshDate = Date(i); 
ThreshID = CompID(i); 

[Peter Perkins]

Answered here: https://www.mathworks.com/matlabcentral/answers/1593449-organising-dates-based-on-user-id-and-compute-weekly-average

Answer 1

[Chris]

I don't see where WaveHeight is declared, but you can calculate a duration by subtracting datetimes.

ThreshDate = datetime('now'); 
pause(1); 
newDate = datetime('now'); 
dur = newDate-ThreshDate

dur = duration
   00:00:01

To get the answer in seconds (similarly for minutes or hours):

converted = seconds(dur)

converted = 1.0100