Solar System
The overall structure of the charted regions of the Solar System consists of the Sun, four relatively small inner planets surrounded by a belt of mostly rocky asteroids, and four giant planets surrounded by the Kuiper belt of mostly icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune.
Solar calendar
The Islamic calendar, which is a purely lunar calendar and has a year, whose start drifts through the seasons and so is not a solar calendar.
The Maya Tzolkin calendar, which follows a 260-day cycle, has no year, so is not a solar calendar.
Also any calendar calendars synchronized only to the synodic period of Venus would not be solar.