There are at least two bands with the name "Zwielicht"
1) The first one is a German Black Metal Band founded in 2005.
In 2006 they released their first 5 track Demo "Leibestod". http://www.zwielicht-bm.de (now defunct)
2) The seecond one is a German Medieval Rock Band founded in 2007.
In 2009 they released their first Album "Zeitlos". http://zwielicht-band.de