rw950431 on Convert counter values to rate

Have you tried the datetime(year.month,day,hour,minute,second) format (see https://au.mathworks.com/help/matlab/ref/datetime.html)

This works for me using the public channel..

% Enter your MATLAB Code below
[data] = thingSpeakRead(12397,'Fields',[1 4],'DateRange',[datetime(2014,8,8,0,0,0),datetime(2014,8,8,1,0,0)],'OutputFormat','table')


data = 

  Timestamps  WindDirectionNorth0Degrees TemperatureF
 ____________________ __________________________ ____________

 08-Aug-2014 00:00:22 0 78.6 
 08-Aug-2014 00:01:22 270 78.6 
 08-Aug-2014 00:02:22 270 78.6 
 08-Aug-2014 00:03:22 225 78.6 
 08-Aug-2014 00:04:22 135 78.6 
 08-Aug-2014 00:05:22 315 78.7 
 08-Aug-2014 00:06:22 45 78.7