Being an Aussie I want to use date formats like 'd/m/Y H:i' or 'D d/m/Y' in my Ext components. In my Air app I was getting errors in the Ext-all.js file in the createNewFormat() method (Ext 2.2).

This post explains why:

You need to precompile the date formats to avoid the AIR security errors. I found that it was easy to do this:
PHP Code:
Date.precompileFormats("d/m/Y H:i|D d/m/Y"); 
in my code before those date formats were used. Note that you must NOT include spurious spaces eg "d/m/Y H:i| D d/m/Y" (space before the D) threw an error (copy and paste error).