>>> I’ve thought it was Sunday all day today until I realised no one has put their bins out for collection tomorrow
Now you're really complicating things, Vagus. I also tend to use 'bin day' as a reference point, so that I know where in the week I am. That's fine as long as there's not a bank holiday in the week though, as that puts our bin collections back by a day.
Like you, our bins are collected on Mondays (or on a Tuesday when there's a bank holiday on the Monday) but, since we've just had a bank holiday on a Friday, I don't know whether 'bin day' will be Monday or Tuesday in the coming week. That's really going to throw me out!