Potting data in time consequtive sequential figures

I am writing a gui app and where user inputs starttime, endtime and time windows for each dataset to be displayed. I would like to plot my data in time windows specified by the user, with figures plotting the points in consequtive time order, e.g for 1 h time window: fig 1 : from 00:00:00 till 01:00:00, fig 2: from 01:00:00 till 2:00.00. Also there are multiple variables and user can choose up to 5 variables to be plotted as subplots in each figure and each figure should have ''yes'' and ''no'' button. Here is my code: (text in bold is added only here)

M=str2double(answer(3,1))/24; % time interval in days from the uder input
handles.M=M;
N=datenum(End-Start) %end and start specified by the uder earlier
noofwindows=ceil(N/M) % how many figures with graphs will be displayed - Maybe it shouldn't be a ceiling function??
handles.noofwindows = noofwindows; 
%% (the above is in a different callback function hence the handle)

noofwindows=handles.noofwindows 
M=handles.M
Start=handles.Start;
NewData=handles.NewData;
row1=find(NewData(1:end, 1)==Start+M);
nfiles = noofwindows; 
for i = 1:nfiles   

        % Create a new figure for the current data file
        hFig = figure(i);
        clf
        set(hFig,'position',[20,50,1500,700])        

        % Plot the data
        if n==5

            for k= 0:noofwindows
 
                N_sp = 5;
                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*M,indx(1)))
                legend(char(list(1,indx(1))))
                title('Data for XXX','fontsize',10)
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1:(k+1)*row1,indx(2)))
                legend(char(list(1,indx(2))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(3)))
                legend(char(list(1, indx(3))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(4)))
                legend(char(list(1, indx(4))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(5)))       
                legend(char(list(1, indx(5))))
                datetick
            end
        elseif n==4
            for k= 0:noofwindows
                
                M=handles.M
                N_sp = 4;
                
                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1:(k+1)*row1,indx(1)))
                legend(char(list(1, indx(1))))
                title('KVB data for sand detection','fontsize',10)
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(2)))
                legend(char(list(1, indx(2))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(3)))
                legend(char(list(1, indx(3))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(4)))
                legend(char(list(1, indx(4))))
                datetick
            end
        elseif n==3
            for k= 0:noofwindows
                
                M=handles.M
                N_sp = 3;

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(1)))
                legend(char(list(1, indx(1))))
                title('KVB data for sand detection','fontsize',10)
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(2)))
                legend(char(list(1, indx(2))))
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(3)))
                legend(char(list(1, indx(3))))
                datetick
            end

        elseif n==2
            for k= 0:noofwindows
                M=handles.M
                N_sp = 2
                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(1)))
                legend(char(list(1, indx(1))))
                title('KVB data for sand detection','fontsize',10)
                datetick

                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(2)))
                legend(char(list(1, indx(2))))
                datetick
            end

        elseif n==1
            for k= 0:noofwindows
                M=handles.M
                N_sp = 1
                idx_sp = idx_sp + 1;
                h(idx_sp) = subplot(N_sp,1,idx_sp);
                hold on
                plot(NewData((k*row1)+1 :(k+1)*row1,1),Variables((k*row1)+1 :(k+1)*row1,indx(1)))
                legend(char(list(1, indx(1))))
                title('KVB data for sand detection','fontsize',10)
                datetick
            end
        else
            close figure(i)
        end
    % Let the user to label the data "Yes" or "No"
        GUI_LabelSandPattern(hFig);        

        % wait for the figure hFig to close before we run into the next iteration  
        waitfor(hFig);  

    end

At the moment my code only plots Fig 1 with data time from 00:00:00 til 01:00:00 (when user inputs start time 00:00:00 and end time 10:00:00). The arror I am getting is:
Error using subplot (line 326)
Index exceeds number of subplots.
Error in GUI_SandData_KVB1Final>pushbutton3_Callback (line 478)
                h(idx_sp) = subplot(N_sp,1,idx_sp);
Error in gui_mainfcn (line 95)
        feval(varargin{:});
Error in GUI_SandData_KVB1Final (line 42)
    gui_mainfcn(gui_State, varargin{:});
Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)GUI_SandData_KVB1Final('pushbutton3_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

I am not sure what should I change to make the loop work properly. Thanks in advance! Any help appreciated.