How can I save custom date formats to the Input Tool dialog in MATLAB R2022b?

Is there a way to save (or set) custom datetime formats in the Import Tool dialog so that they can be reused after restarting MATLAB R2022b and/or Import Tool? My use case is that I often need to enter the following custom format:

yyyy.DDD.HH:mm:ss

It would be helpful to have that appear as a custom option at the top of the list after it has been used. It does that now if I don't close the Import Dialog, but it doesn't reappear if I close the Import Dialog or restart MATLAB. I would prefer to have a persistent list of the most recently used formats instead of (or at the top of) the existing list of sample formats.

The image below shows the custom datetime format that I have created, which I would like to remain persistent:

Answer 1

[MathWorks Support Team]

A way to use custom formats is to import your data programmatically. This would involve importing a data file using code that performs custom date formatting without having to manually specify it. For example, for the following “datafile.txt” file:

2000.003.06:09:12
2001.004.07:10:13
2002.005.08:11:14

You can use the “readtable” MATLAB function and its “Format” property to specify a custom date format as follows:

T = readtable("datafile.txt", "Delimiter", " ", "Format", "%{yyyy.DDD.HH:mm:ss}D %d");

For more information regarding the “readtable” function, please refer to the documentation linked below:

https://www.mathworks.com/help/releases/R2022b/matlab/ref/readtable.html

Saving the custom format in the graphical interface is something our development teams are considering for future MATLAB releases.