A year _in the ISO-8601 calendar system, such as {@code 2007}. !(p) {@code Year} is an immutable date-time object that represents a year. Any field that can be derived from a year can be obtained. !(p) !(b)Note that years _in the ISO chronology only align with years _in the Gregorian-Julian system for modern years. Parts of Russia did not switch to the modern Gregorian/ISO rules until 1920. As such, historical years must be treated with caution.</b> !(p) This class does not store or represent a month, day, time or time-zone. For example, the value "2007" can be stored _in a {@code Year}. !(p) Years represented by this class follow the ISO-8601 standard and use the proleptic numbering system. Year 1 is preceded by year 0, then by year -1. !(p) The ISO-8601 calendar system is the modern civil calendar system used today _in most of the world. It is equivalent to the proleptic Gregorian calendar system, _in which today's rules for leap years are applied for all time. For most applications written today, the ISO-8601 rules are entirely suitable. However, any application that makes use of historical dates, and requires them to be accurate will find the ISO-8601 approach unsuitable.