The Orthodox Andorian Vengeance Cycle was a time period within Andorian history. The Andorian calender system reverts to its 330th iteration in the year 2400. In the alternate timeline known as the War of the Prophets, it marked the occassion when the blue wormhole would merge with the red wormhole and wipe out all existence by the creation of a warp 10 shockwave. (DS9 - Millennium novel: The War of the Prophets)