Years

The year, often symbolized as yr or a, is a unit of time based on the orbital period of the Earth around the Sun. In the widely used Gregorian calendar, a common year contains 365 days, while a leap year contains 366 days to align with the actual solar cycle of roughly 365.2422 days. Scientific and astronomical standards frequently employ the Julian year, which is formally defined as exactly 365.25 days, or precisely 31,557,600 SI seconds.