A date and time interval is special value to be used to increment or decrement a date or a time at a given date or time unit. A data and time interval should be expression in the format of "INTERVAL expression unit", where "unit" and "expression" should follow these rules:
unit - expression value format
MICROSECOND - MICROSECONDS
SECOND - SECONDS
MINUTE - MINUTES
HOUR - HOURS
DAY - DAYS
WEEK - WEEKS
MONTH - MONTHS
QUARTER - QUARTERS
YEAR -YEARS
SECOND_MICROSECOND - 'SECONDS.MICROSECONDS'
MINUTE_MICROSECOND - 'MINUTES.MICROSECONDS'
MINUTE_SECOND - 'MINUTES:SECONDS'
HOUR_MICROSECOND - 'HOURS.MICROSECONDS'
HOUR_SECOND - 'HOURS:MINUTES:SECONDS'
HOUR_MINUTE - 'HOURS:MINUTES'
DAY_MICROSECOND - 'DAYS.MICROSECONDS'
DAY_SECOND - 'DAYS HOURS:MINUTES:SECONDS'
DAY_MINUTE - 'DAYS HOURS:MINUTES'
DAY_HOUR - 'DAYS HOURS'
YEAR_MONTH - 'YEARS-MONTHS'