Changing the Serial Date to String when saving as .txt file

I have a 20197x44 matrix where the first column is the serial date. I want to change the serial date to the format 'mmm dd, yyyy HH:MM:SS.FFF AM' when I am saving to a text file. (This data is for a client who has requested the date in this format).

I cannot figure out how to do this successfully. I have tried several approaches that are close but not working. I used a code to add column headers (shown below). Would I do something similar but use columns instead of rows?

% SAMPLE 1:
filename = 'Sample 1 Data.txt';
fileID = fopen(filename,'w+');
[rows, columns] = size(h1);
for index = 1:rows    
    fprintf(fileID, '%s,', h1{index,1:end-1});
    fprintf(fileID, '%s\n', h1{index,end});
end 

fclose(fileID);
dlmwrite(filename, rod1,'-append', 'delimiter', ',');

where h1 is the cell array of the column titles. Any suggestions greatly appreciated. Thank you

- Pamela

Answer 1

[Walter Roberson]

fprintf(fileID, '%s\n', datestr(h1(:,1), 'mmm dd, yyyy HH:MM:SS.FFF AM'))

The place it gets more complicated is if you want to put additional information on the same row and you want to do it all with one fprintf() instead of looping over the rows.

[Pw]

Aw! Thank you.

The rest of the row contains numeric data. I don't need to do it all in one fprintf(), looping would be fine. How would I write this loop? I'm not as familiar with loops as I'd like to be so learning how to write one for this would be a great exercise. I'm assuming I could use a similar format as the one I used for the column headers....?