The practice of working from home on a Friday. Has become widespread with the advent of the broadband connection. The practice originates from the 1980s, when bankers, lawyer and other professionals elected to have a day of dressing casually on Friday, so they would not ruin their suits with spilt beer in the evening. This was known as dress-down Friday. However the act of selecting casual clothes prroved beyond these individuals who now simply just work from home in their dressing gown.
John is taking a Dressing-gown Friday, as he had a working dinner last night.