HOW TO CALCULATE AGE | SQL Server | SQL Tutorial

DATEDIFF() Function In SQL Server is used to calculate difference in two dates based on specific intervals of date ,
Ex:
year, yyyy, yy = Year
quarter, qq, q = Quarter
month, mm, m = month
dayofyear = Day of the year
day, dy, y = Day
week, ww, wk = Week
weekday, dw, w = Weekday
hour, hh = hour
minute, mi, n = Minute
second, ss, s = Second
millisecond, ms = Millisecond

SYNTAX:
DATEDIFF(interval, date1, date2)