Duvet day
A duvet day is a formal allowance of time off given by some employers, most commonly in the United Kingdom and United States.
It can be stipulated formally in a contract of employment and is considered part of the remunerations package along with holiday allowance. The term has also since become used by people to reference taking a day off work for no normally accepted reason (such as mild sickness, grievance or holiday) even if they have no official duvet day entitlement with their employer.