Heaven Shall Burn are a German extreme metal band from Saalfeld, formed in 1996. The band consists of vocalist Marcus Bischoff, guitarists Maik Weichert and Alexander Dietz, bassist Eric Bischoff and drummer Christian Bass. They are currently signed to Century Media. They have released eight studio albums, as well as a number of other records.

After signing to Century Media in January 2004, Heaven Shall Burn's label debut Antigone was released on April 26. The LP version of the album was released through Lifeforce. Shortly after the release of Antigone Heaven Shall Burn filmed a music video for the song "The Weapon They Fear". Antigone was further promoted during a headlining tour through Europe, supported by Maroon. On this tour they appeared at the hardcore punk festival Fluff Fest for the third and thus final time. After the 2004 Indian Ocean tsunami, Heaven Shall Burn teamed up with Napalm Death and the Haunted and released the split single Tsunami Benefit to raise money for charity. The single was limited to 1,000 hand-numbered copies and was sold on two exclusive Napalm Death shows. In March 2005, Heaven Shall Burn appeared at the Independence D Festival in Japan. In summer 2005 Heaven Shall Burn and Caliban's second split album The Split Program II was released through Lifeforce Records. Shortly after participating at the Hell on Earth Tour 2005 Heaven Shall Burn announced that guitarist Patrick Schleitzer was leaving the band and Alexander Dietz, who played the guitar during the Hell on Earth Tour, would become the new guitarist. Heaven Shall Burn played a special farewell show with Schleitzer in Saalfeld. Following a quiet period, Heaven Shall Burn announced they had recorded a new album titled Deaf to Our Prayers, which was released on August 28, 2006. After the release of "Counterweight", as the first track of the new album, Deaf to Our Prayers entered the German album charts at #65, being the first Heaven Shall Burn album to enter record sales charts. During Summer 2006, Heaven Shall Burn played shows at Summer Breeze Open Air and other festivals. Live footage, recorded at Summer Breeze was later used in the "Counterweight" music video. In September and October they headlined the Hell on Earth Tour 2006 on the European mainland, also part of the tour were Cataract, Maroon, and God Forbid. At the end of the year they embarked co-headlining tour with Caliban through Germany and Belgium.

Answer the following question by taking a quote from the article: when was it released?
April 26.