The YEAR function returns the year part of a value.

>>-YEAR--(--expression--)--------------------------------------><
- expression
- An expression that returns a value of one of the following built-in
data types: a date, a timestamp, a character string, a graphic string,
or a numeric data type.
- If expression is a character or graphic
string, it must not be a CLOB or DBCLOB, and its value must be a valid
string representation of a date or timestamp. For the valid formats
of string representations of dates and timestamps, see String representations of datetime values.
- If expression is a number, it must be
a date duration or timestamp duration. For the valid formats of datetime
durations, see Datetime operands and durations.
The result of the function is a large integer. If the
argument can be null, the result can be null; if the argument is null,
the result is the null value.
The other rules depend on the data type of the argument:
- If the argument is a date or a timestamp or a valid character-string
representation of a date or timestamp:
The result is the year part
of the value, which is an integer between 1 and 9999.
- If the argument is a date duration or timestamp duration:
The
result is the year part of the value, which is an integer between
-9999 and 9999. A nonzero result has the same sign as the argument.