how to make datetime data readable and convert to julian date?

greeting sir, I want to convert date time with YYYY/MM/DD HH:MM:SS format in my file to julian date. When I load my data, the datenumber changed to NaN

This is what I've tried

clc;clear; close all;


% Specify the folder where the files live.
myFolder = 'C:\ZTD\CSV';
% Check to make sure that folder actually exists.  Warn user if it doesn't.
if ~isfolder(myFolder)
    errorMessage = sprintf('Error: The following folder does not exist:\n%s\nPlease specify a new folder.', myFolder);
    uiwait(warndlg(errorMessage));
    myFolder = uigetdir(); % Ask for a new one.
    if myFolder == 0
         % User clicked Cancel
         return;
    end
end
Allfile = fullfile(myFolder, '*.txt'); % Change to whatever pattern you need.
List = dir(Allfile);
for k = 1 : length(List)
    sites = List(k).name;
     num = readmatrix(sites,"NumHeaderLines",1);
num(:,end)=[];
      time = num(1:end,1);
       %   % julian date corresponding to 2000-01-01 00:00:00.0
mjd20000 = 51544;

How to make my date time data readable and calculate it to julian date?

Answer 1

[VBBV]

use readtable instead of readmatrix

D = readtable('dd.txt')  % use readtable 

Warning: Column headers from the file were modified to make them valid MATLAB identifiers before creating variable names for the table. The original column headers are saved in the VariableDescriptions property.
Set 'VariableNamingRule' to 'preserve' to use the original column headers as table variable names.

D = 4259×19 table
    Date_Asia_Jakarta_    Tempin__C_    Temp__C_    Chill__C_    Dewin__C_    Dew__C_    Heatin__C_    Heat__C_    Humin___    Hum___    Wspdhi_m_s_    Wspdavg_m_s_    Wdiravg___      Bar_hPa_      Rain_mm_    Et_mm_    Rainrate_mm_h_    Solarrad_W_m__    Uvi__
    __________________    __________    ________    _________    _________    _______    __________    ________    ________    ______    ___________    ____________    __________    ____________    ________    ______    ______________    ______________    _____

     01/01/2022 00:00        27.3         25.3        25.3          NaN        23.3         NaN          25.3         52         89          1.5            1.1            229        {'1,010.90'}       0         NaN            0                 0             0  
     01/01/2022 00:10        27.3         25.1        25.1          NaN        23.3         NaN          25.1         52         90            0              0            226        {'1,010.80'}       0         NaN            0                 0             0  
     01/01/2022 00:20        27.3           25          25          NaN        23.2         NaN            25         52         90            0              0            226        {'1,010.40'}       0         NaN            0                 0             0  
     01/01/2022 00:30        27.3         24.9        24.9          NaN        23.4         NaN          24.9         52         91            0              0            226        {'1,010.20'}       0         NaN            0                 0             0  
     01/01/2022 00:40        27.3         24.9        24.9          NaN        23.4         NaN          24.9         52         91            0              0            226        {'1,010.30'}       0         NaN            0                 0             0  
     01/01/2022 00:50        27.2         24.8        24.8          NaN        23.3         NaN          24.8         52         91          0.5            0.4            226        {'1,010.20'}       0         NaN            0                 0             0  
     01/01/2022 01:00        27.1         24.8        24.8          NaN        23.3         NaN          24.8         52         91            0              0            226        {'1,010.10'}       0         NaN            0                 0             0  
     01/01/2022 01:10        27.2         24.8        24.8          NaN        23.5         NaN          24.8         52         92            0              0            226        {'1,010.20'}       0         NaN            0                 0             0  
     01/01/2022 01:20        27.2         24.8        24.8          NaN        23.3         NaN          24.8         52         91            0              0            226        {'1,010.10'}       0         NaN            0                 0             0  
     01/01/2022 01:40        27.1         24.8        24.8          NaN        23.5         NaN          24.8         52         92            0              0            226        {'1,010'   }       0         NaN            0                 0             0  
     01/01/2022 01:50        27.1         24.8        24.8          NaN        23.3         NaN          24.8         52         91          0.5            0.1            226        {'1,009.80'}       0         NaN            0                 0             0  
     01/01/2022 02:00        27.1         24.8        24.8          NaN        23.3         NaN          24.8         52         91            0              0            226        {'1,009.80'}       0         NaN            0                 0             0  
     01/01/2022 02:10        27.1         24.8        24.8          NaN        23.3         NaN          24.8         52         91          0.5            0.5            226        {'1,009.80'}       0         NaN            0                 0             0  
     01/01/2022 02:20        27.1         24.7        24.7          NaN        23.2         NaN          24.7         52         91          0.5            0.5            225        {'1,009.80'}       0         NaN            0                 0             0  
     01/01/2022 02:30          27         24.7        24.7          NaN        23.2         NaN          24.7         52         91          0.5            0.2            226        {'1,009.80'}       0         NaN            0                 0             0  
     01/01/2022 02:40          27         24.6        24.6          NaN        23.1         NaN          24.6         52         91            0              0            226        {'1,009.90'}       0         NaN            0                 0             0  

dt = D.Date_Asia_Jakarta_

dt = 4259×1 datetime array
   01/01/2022 00:00
   01/01/2022 00:10
   01/01/2022 00:20
   01/01/2022 00:30
   01/01/2022 00:40
   01/01/2022 00:50
   01/01/2022 01:00
   01/01/2022 01:10
   01/01/2022 01:20
   01/01/2022 01:40
   01/01/2022 01:50
   01/01/2022 02:00
   01/01/2022 02:10
   01/01/2022 02:20
   01/01/2022 02:30
   01/01/2022 02:40
   01/01/2022 02:50
   01/01/2022 03:00
   01/01/2022 03:10
   01/01/2022 03:20
   01/01/2022 03:30
   01/01/2022 03:40
   01/01/2022 03:50
   01/01/2022 04:00
   01/01/2022 04:10
   01/01/2022 04:20
   01/01/2022 04:30
   01/01/2022 04:40
   01/01/2022 04:50
   01/01/2022 05:00

jd = juliandate(dt)

jd = 4259×1

1.0e+06 * 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596 2.4596

[adhi dermawan]

Hello sir, It worked on julian date but tried to convert it to modified julian date but I got this error

Error using mjuliandate (line 78)
Expected input to be one of these types:

double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64

Instead its type was datetime.

Error in csvcoba (line 28)
mjd = mjuliandate(dt);
 

[VBBV]

use the below

mjd = mjuliandate(jd);

in place of

mjd = mjuliandate(dt);

[adhi dermawan]

I got another error sir

Error using mjuliandate (line 94)
Input must be an M-by-6 or M-by-3 matrix containing M full or partial date vectors, a date string and the format for the
date string, or three or six separate numeric arrays of the same size.

Error in csvcoba (line 29)
mjd = mjuliandate(jd);

[adhi dermawan]

I solved it in another way. thank you for helping me sir