The Day Quadrant lies in the Vega Sector and consists of the Acrus, Alliance, Ariel, Blackmane, Caliban, Cambria, Delius, Dieno, Enyo, Hell's Kitchen, Krieger, Lafayette, McAuliffe, McDaniel's World, Montrose, Pephedro, Tali and Tamayo systems.
The Day Quadrant has been an important location in the Terran-Kilrathi War. In 2634, the war began here when the Kilrathi Empire destroyed the civilian vessel "TCS Anna Magdalena" at Dieno in what was a raid against civilian shipping. War was declared by the Terran Confederation after the incident.
The Day Quadrant is the site of the infamous Enyo Engagement and the Battle of McAuliffe, the opening battles of the War. Many star systems fell to the Kilrathi during the War with many others ravaged in major engagements. The quadrant was liberated with the success of the Vega Sector Campaign of the 2650s, but was continually attacked as the Kilrathi regained their momentum later in the War. By 2669, Ariel, Caliban, Blackmane, among others were all captured, with systems like Delius totally ravaged.
The quadrant was likely freed after the War's end in 2669.