Licht some cases—portions of scenes. These modules may be segments (e.g., the eleven instrumental solo sections from "Orchester-Finalisten" from "Mittwoch"), or layers (e.g., the electronic "Oktophonie" layer from the second act of "Dienstag" or the "Klavierstück XIII" version of the first scene of "Samstag" ("Luzifers Traum"), with the bass voice omitted), or a combination of the two (e.g., the vocal sextet "Menschen, hört" and the "Bassetsu-Trio", which are two layers of the "Karusel" subscene from "Michaelion", the fourth scene of "Mittwoch"). There are seven operas, each named for a day of the week, whose subject matter reflects attributes associated in traditional
Eight-day week popularity of the seven-day rhythm won and the eight-day week disappeared. The cycle of seven days, named after the sun, the moon, and the five planets visible to the naked eye, was already customary in the time of Justin Martyr, who wrote of the Christians meeting on the Day of the Sun (Sunday). Emperor Constantine eventually established the seven-day week in the Roman calendar in AD 321. The Celts used periods of darkness such as night and winter to begin their calculations of time. This meant that the first period of time in a "week" was a night, followed by