EXTRACT(DAY FROM MAX(joindate)-MIN(joindate)) AS DateDifference
EXTRACT(DAY FROM created-updated)
EXTRACT(HOUR FROM (updated - created)) AS HourDifference
CENTURY: It is the number of centuries
DAY: It is the day of the month (1-31) or the number of days
DECADE: It is the decade that is the year divided by 10.
DOW: It is the day of the week Sunday (0) to Saturday (6).
DOY: it is the day of the year that ranges from 1 to 366.
EPOCH: It is the total number of seconds in the interval
HOUR: It is the number of hours
MILLENNIUM: It is the number of millennium
MILLISECONDS: It is the second’s field, including fractional parts,
MINUTE: It is the minute (0-59) or a number of minutes.
MONTH: The number of months (1-12).
SECOND: It is the number of seconds.
WEEK: It is the number of weeks
YEAR: It is the year.