EXTRACT() let you extract part of a date or datetime.

Here are a list of parameters that can be used

MICROSECOND
SECOND
MINUTE
HOUR
DAY
WEEK
MONTH
QUARTER
YEAR
SECOND_MICROSECOND
MINUTE_MICROSECOND
MINUTE_SECOND
HOUR_MICROSECOND
HOUR_SECOND
HOUR_MINUTE
DAY_MICROSECOND
DAY_SECOND
DAY_MINUTE
DAY_HOUR
YEAR_MONTH

 

Example (Seconds)

SELECT EXTRACT(YEAR FROM,'1999-02-03 23:59:59')

Returns

1999