How to deal with objects that are always changing?

Hi, I have a section of where user could select the date on the app based on month. So if I am producing test script this month, the next month when the test scripts are executed it will not matched as it is no longer the same. I have experience in UFT, it use regular expression and descriptive programming approach to deal with changing objects. For Katalon, I found that locator strategy could be the solution for this? But I have tried which I want the index of the object to be identified instead of its desc content, but it still not working. Could anyone share some experience about it? Thanks