The following table shows the expected form of the expr argument for each unit value.
unit ValueExpected expr Format
MICROSECONDMICROSECONDS
SECONDSECONDS
MINUTEMINUTES
HOURHOURS
DAYDAYS
WEEKWEEKS
MONTHMONTHS
QUARTERQUARTERS
YEARYEARS
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'