Fashion is not Art. Art can’t be bothered with being fashionable, if it wants to do what art is supposed to be doing. Fashion is a product of its own time, while also being part of what defines it. Art, on the deeper levels than apparences, the means of production and presentation etc, isn’t bound to its time. The period in which a work of art was made in, is anacdotal in relations to the artistic substance of the work itself. Unless it’s bad art of course, then, the date of creation is probably the only significant detail.