A clock displays the start of the morning shift outside the General Motors German unit Adam Opel AG car factory in Bochum. Credit: Wolfgang Rattay/ Reuters Had a good bank holiday, did you? Enjoyed the extra day off, revelled gloriously in the prospect of a short four-day week ahead? For your sake, I hope you weren’t like me who, not for the first time, only realised it was a three-day extravaganz