DATEDIFF

DATEDIFF([Created On], [Completed On], 'year')

Syntax

DATEDIFF(start date, end date, date part)

Returns the count of the specified date part boundaries crossed between the specified start date and end date.

start date: Date calculation created using date functions, data fields or constants.

end date: Date calculation created using date functions, data fields or constants.

date part: Text constant which can be chosen from minute, hour, dayofweek, dayofmonth, dayofyear, week, month, quarter, year