What are the subtle characteristics that make Friday a Friday?

You can guess its a Friday in Tokyo because the already high level of office dressiness is elevated to factor in after-work socialising – an extra whiff of perfume, finer dresses, a little bit more heel. But why? In what cultures are people likely to already wear and carry the objects they need for the day when they leave home? In which cities are you more likely to head home and get changed before heading out? To what extent is it based on the immediacy of after-work socialising rituals? Or commuting times? Or the rhythm of the city? And what are the consequent opportunities for product and services designers?