Converting datenum to datetime when using writetable

Hi all

I want to export some datetime data to excel. I dont know how.

In addition, for certain years, there are no values. I show this by replacing values by zero

A = datenum(t0_pos1); %values 2021
B = datenum(t0_pos12); %values 2022
if isempty(B)==1
    B=zeros(1,1);
end
C = [];
C(:,1) = A;
C(:,2) = B;
borjan=array2table(C,'VariableNames',{'2021','2022'});
writecell(G2,'asd2.xlsx','Sheet',1,'Range','H2')
writetable(borjan,'asd2.xlsx','Sheet',1,'Range','H3')

I got numbers into excel, but I want the datenum to be converted to datetime (yy-mm-dd-hh).

[Stephen23]

Do not convert perfectly good DATETIMEs to deprecated DATENUMs!

You can easily merge two DATETIME arrays using the EMPTY method of the appropriate class:

A = datetime(2023,1,1:9).'

A = 9×1 datetime array
   01-Jan-2023
   02-Jan-2023
   03-Jan-2023
   04-Jan-2023
   05-Jan-2023
   06-Jan-2023
   07-Jan-2023
   08-Jan-2023
   09-Jan-2023

B = datetime(2023,1,[])

B = 

  0×0 empty datetime array

C = datetime.empty;
C(1:numel(A),1) = A;
C(1:numel(B),2) = B

C = 9×2 datetime array
   01-Jan-2023   NaT        
   02-Jan-2023   NaT        
   03-Jan-2023   NaT        
   04-Jan-2023   NaT        
   05-Jan-2023   NaT        
   06-Jan-2023   NaT        
   07-Jan-2023   NaT        
   08-Jan-2023   NaT        
   09-Jan-2023   NaT        

and then WRITEMATRIX as usual. Avoid deprecated DATENUM, DATESTR, and DATEVEC.

Answer 1

[Cris LaPierre]

You convert your datetimes to datenums, and then write those numbers to Excel, which is what you are seeing.

Don't convert your datetimes to datenums. Then, you can use the format cells option in Excel to set the date format it gets displayed with.