Here's a date for your diary. The 24th of July. It's next Friday, and that's when wearing a mask becomes compulsory in England's shops and supermarkets. There'll be fines if people don't follow the rules. £100, which goes down to half that if you pay within a fortnight of the fine being handed out. In Scotland, face coverings in shops have been mandatory since 10 July. Shoppers in Wales and Northern Ireland don't have to wear them, but it's under review. This brings England into line with Germany, Spain and Italy.