I have a problem with drawing on the timeline

clear all ; clc ; clf ;
 set(gcf,'color','w')
%% load data
 filehtm = dir('moving_windown_test.xlsx') ;
              
 for ii = 1 : length(filehtm);
     filehtm(ii).name
     [num,str,xlsdata] = xlsread(filehtm(ii).name) ;    %num數值 str字串
 end
%% set time
 time = num(:,1) ;
 tide_detrend = num(:,2) ./ 1000 ;
 tide = tide_detrend ; 
 tide_raw = tide_detrend;

 %% set time
 YYYY = fix(time/1000000) ;
 
 MM   = mod(fix(time/10000),100) ;
 DD   = mod(fix(time/100),100) ;
 HH   = mod(time,100) ;
 tt   = datenum(YYYY,MM,DD,HH,0,0) ;
%% loop movingwindown
 for  k = 1:1:5
 yyyy(k) = 1960 +k;

 
 t1 = datenum(  yyyy(k),1,1) : 1/24 : datenum(  yyyy(k)+1,1,1); 
 t1(end)=[];

  year = YYYY;
 index = find(year ==  yyyy(k));
  t = tt(index); % movingwindown 時間
Q1(k) = prctile(tide(index), 25) ;
Q3(k) = prctile(tide(index), 75);
IQR(k) = Q3(k) - Q1(k)   ;
upper(k) = Q3(k) + 1.5*IQR(k)
lower(k) = Q1(k) - 1.5*IQR(k)
tide_outline = tide(index);
raw_tide = tide(index);
tide_outline(tide_outline > upper(k) | tide_outline < lower(k)) = nan;

 
 for j = 1 : length(t1);
     if  (isempty(find(t==t1(j))));
         r_tide(j) = nan ;
     else
         r_tide(j) = tide_outline(find(t==t1(j))) ;
     end 
 end

  for j = 1 : length(t1);
     if  (isempty(find(t==t1(j))));
         r_tide(j) = nan ;
     else
         r_tide_1(j) = raw_tide(find(t==t1(j))) ;
     end 
 end

  for  i = 1 : length(t1) ;
  field_day(i) = (yyyy(k)+(i - 1) * 60 * 60 / 86400/365) ;
         end    
plot([yyyy(k),yyyy(k)+1],[upper(k),upper(k)],'-r');hold on
plot([yyyy(k),yyyy(k)+1],[lower(k),lower(k)],'-b');
%            plot(field_day,r_tide, 'b' ) ; hold on %remove outliner
          
            plot(field_day,r_tide_1 );hold on % rawdata
 end