Reviewers like to say that this or that work of art is ‘demanding’, but unless they’ve watched Christian Marclay’s The Clock, they don’t know what they’re talking about.

The Clock makes demands beyond any art I’ve ever come across: it demands the viewer be awake all night; it demands unwavering attention, hour after hour; it imposes hunger, thirst, exhaustion, an uncomfortably full bladder. Twenty-four hours of movie with no beginning and no end, The Clock is a strange sort of masterpiece.