Convert a Matrix column to date

I have a matrix 5556x2 double which both columns are read as numbers. I want to convert to first column to be read as dates. the format is yyyyMMdd as in, 20010130. My code for a loop is here that works but in the final product I want the entire first column to be read as dates rather than numbers so when I plot the two columns the X axis is understandable.

len2 = 0;

for i = 1:16 
    year = i+2001;
    filename =['CRND0103-',sprintf('%4.4d',year),'-AK_Barrow_4_ENE.txt'];
    formatSpec = '%*5s%9f%*7*s%*8*s%*8*s%*8*s%*8f%8f%[^\n\r]';
    fileID = fopen(filename,'r');
    dataArray = textscan(fileID, formatSpec, 'Delimiter', '', 'WhiteSpace', '', 'TextType', 'string',  'ReturnOnError', false);
    fclose(fileID);
    bar = [dataArray{1:end-1}];
    len1 = length(bar);
    barrow(len2+1:len1+len2,:)= bar(:,:);
    len2 = length(barrow);
end;

barrow(barrow == - 9999) = NaN;

[Rik]

If you use datenum as x values, the xticks should automatically show dates. Is that what you are looking for? I'm a little confused about how your text relates to the code.

Answer 1

[KL]

Try something like this,

dt = [20110130; 20110131; 20110201]; %your column
d = datetime(num2str(dt),'InputFormat','yyyyMMdd')