datetime default format by version and operating system

On my Mac running R2022a, if I enter datetime('now') without specifying any format, I get 2023130090948. That is, it's 2023, the 130th day, at 9:09:48 AM. But on Windows running R2020b, the same input gives 10-May-2023 09:09:48. Is this difference due to the different operating systems, or different Matlab versions, or what? Where is the documentation?

Answer 1

[Steven Lord]

What are your datetime format preferences settings?

Can you confirm that you're using the datetime function included as part of MATLAB and not one that you downloaded?

which -all datetime

/MATLAB/toolbox/matlab/datatypes/datetime/@datetime/datetime.m  % datetime constructor
/MATLAB/toolbox/matlab/bigdata/@tall/datetime.m                 % tall method
/MATLAB/toolbox/parallel/parallel/@codistributed/datetime.m     % codistributed method

[Rich006]

On my Mac:

which -all datetime

/Applications/MATLAB_R2022a.app/toolbox/finance/ftseries/@fints/private/datetime.m      % Private to @fints
/Applications/MATLAB_R2022a.app/toolbox/matlab/bigdata/@tall/datetime.m                 % Shadowed tall method
/Applications/MATLAB_R2022a.app/toolbox/parallel/parallel/@codistributed/datetime.m     % Shadowed codistributed method
/Applications/MATLAB_R2022a.app/toolbox/matlab/datatypes/datetime/@datetime/datetime.m  % Shadowed datetime constructor

The Windows machine is on a server that I don't have access to at the moment. The same format difference shows up when I write to a text file with fprintf, which is what I'm trying to do. I didn't think changing the Command Window preference for datetime format would affected printing to file, but it did. Anyway, it's clear I should specify the format I want in my output file, rather than assuming the default format is always the same.