Is there any time limit in the List view of the iPhone Calendar app? Is there any time limit in the List view of the iPhone Calendar app, beyond which we cannot make any entries? Can this limit be changed to something else than the 2 years set by by Apple?
There is no limit in the Calendar itself – you can 'zoom out' by repeatedly tapping the Back button until you're in a screen where each year takes up about a single page. Scroll down to e.g. 2027, and you can create an event in the distant future without problems:

 

The List view does seem to have a built-in limit of two years, which can't be extended by settings.