A period of time akin to the time taken for the Earth to undergo a full cycle of seasons. • The time taken for the Earth to return to the same position along the ecliptic, completing a full cycle of seasons; a tropical year or solar year. • The time taken for the Earth to orbit the Sun with respect to the fixed stars; a sidereal year. • The length of twelve lunations; the time taken for any moon phase to happen twelve times; a lunar year. • The length of a year as marked by a calendar, 365 or 366 days in the Gregorian calendar; a calendar year. • The mean length of a calendar year in the Julian calendar, that is, 365.25 solar days; a Julian year. • An orbital period: the period of one revolution in any particular orbit: The time it takes for any astronomical object (such as a planet, dwarf planet, small Solar System body, or comet) in direct orbit around a star (such as the Sun) to make one revolution around the star. • A period between set dates that mark a year, such as from January 1 to December 31 by the Gregorian calendar, from Tishri 1 to Elul 29 by the Jewish calendar, and from Muharram 1 to Dhu al-Hijjah 29 or 30 by the Islamic calendar. • A scheduled part of a calendar year spent in a specific activity. • A level or grade in school or college. • The proportion of a creature's lifespan equivalent to one year of an average human lifespan (see also dog year).