Experts say that, for most, it will take days for the biological clock and the actual clock to realign

David Aird, 56, a London-based musician, builder, and father of one, had been suffering from migraines for five years before he saw his GP, who broke the news to him that he had a brain tumour the size of a golf ball. It blew his world apart, he tells Charlotte Cripps – but it also means he no longer sweats the small stuff