A discipline of magic that deals with the manipulation of time. Forbidden in Lux, as Time is what the Weave is made up, so magic that manipulates and shreds time manipulates and shreds the Weave itself, and doing so too much could unravel reality itself. As the Weave is also the wall around reality that separates it from the primordial chaos of Paradox, this is generally viewed as undesirable.
Desmun was a noted chronomancer who was pursued and killed due to his work. In a way, he did in fact cause the end of the world, as Esmund - one of him, sort of - ended up using the Door Jamb that partially made use of some of his research, which ultimately cracked the world.