This is another way of saying One of these days is none of these days. ‘I’ll do it one of these days.’ This means that you propose to do whatever it is later on. The result is that it is never done at all.
This is another way of saying One of these days is none of these days. ‘I’ll do it one of these days.’ This means that you propose to do whatever it is later on. The result is that it is never done at all.