Assalamualaikum and good days guys.
Herewith a Draft for coding...
CLC
clear
close all
Raw_Data1 = readable('Ae lab_2011.txt');
Real = Raw_Data1 (:,[1 2 3 4 7 1]);
Real.VariableNames = {'Date', 'Time' , 'Humidity','Irradiance'};
Real.Date.Format = 'dd/Mm/yy';
S = table timetable(Real);

%% Select by month
V = timerange('01/11','31/01/11');
January = S(V);
...
.....
I hope you guys understand and can continue the coding successfully.
Good luck & Thanks
Stay Safe and well!