Problem with date to display in CakePHP 3.8 form field

It sounds like you are only trying to adjust the Time object in the belief that it will change the form inputs. But those are actually under your control:

I have not needed to change the default input templates my self so I don’t have first-hand knowledge, but I believe this is what you want

Also, searching the formum for ‘form template’ will return many posts which may help