Twins with different birthdays leave the internet inexplicably confused

When is a twin not a twin?

An American mother gave birth to twin boys just minutes apart, either side of the turn of the year. That means the first to enter this world was born in December 2015, while his brother has a January 2016 birthday, but they're still clearly twins, right? Right? Not according to some Irish Times readers, who got into what we'll generously describe as a bizarre philosophical argument about the nature of time. https://twitter.com/JoeLeogue/status/683976067946786817 We ought to be surprised, but after this argument between Arsenal fans last year, nothing shocks us any more.