Casual Friday along with dressing casually during the week became very prevalent during the Dot Com hey-day of the late 1990s / early 2000s rooted in a relaxed California-based business culture. The day (also known as Dress-down Friday, or simply Casual day) was an American and Canadian trend which for a time spread to other parts of the world, wherein some offices may celebrate a semi-reprieve from the constrictions of a formal dress code. Whereas, during the rest of the week, business shirts, suits, ties, trousers, and dress shoes would be the norm, on Casual Friday workers might be allowed to wear more casual dress. Some companies might allow jeans, T-shirts, hoodies, and sneakers but others require business casual or smart casual dress. Some offices allow a themed dress down day. On this day, even managers in such workplaces are allowed to dress down.