Beside the rear lens element of many (but not all) Canon lenses is a date code in the form of e.g. "UR0902". This code is also present on many other Canon products including camera bodies.

The first letter, "U", indicates that the lens was made in Canon's Utsunomiya, Japan factory. Prior to 1986, this letter is moved to the last position of the date code.

U = Utsunomiya, Japan
F = Fukushima, Japan
O = Oita, Japan

The second letter, "R", is a year code that indicates the year of manufacture. Canon increments this letter each year starting with A in 1986 and prior to that, A in 1960 without the leading factory code. Here is a table to make things simple:

A = 1986, 1960
B = 1987, 1961
C = 1988, 1962
D = 1989, 1963
E = 1990, 1964
F = 1991, 1965
G = 1992, 1966
H = 1993, 1967
I = 1994, 1968
J = 1995, 1969
K = 1996, 1970
L = 1997, 1972
M = 1998, 1973
N = 1999, 1974
O = 2000, 1975
P = 2001, 1976
Q = 2002, 1977
R = 2003, 1978
S = 2004, 1979
T = 2005, 1980
U = 2006, 1981
V = 2007, 1982
W = 2008, 1983
X = 2009, 1984
Y = 2010, 1985
Z = 2011, 1986

* assumption of continuation being made for future years.

The first two numbers, "09", is the month number the lens was manufactured in. Month 02 is February, month 11 = November. The leading zero of the month code is sometimes omitted.

The next two numbers, "02", are meaningless in determining how old a Canon lens is. This is a Canon internal code (that is occasionally omitted).