Iroquois China Date Codes

The date codes consist of a letter/number code. The LETTER represents the year and the NUMBER the quarter/or month. Block letter bottom stamps were used pre-1940; and script (cursive) bottom stamps were used after 1940.
Year/Month
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
January or 1st Qtr
A-1
B-1
C-1
D-1
E-1
F-1
G-1
H-1
I-1
J-1
February or 2nd Qtr
A-2
B-2
C-2
D-2
E-2
F-2
G-2
H-2
I-2
J-2
March or 3rd Qtr
A-3
B-3
C-3
D-3
E-3
F-3
G-3
H-3
I-3
J-3
April or 4th Qtr
A-4
B-4
C-4
D-4
E-4
F-4
G-4
H-4
I-4
J-4
May
A-5
B-5
C-5
D-5
E-5
F-5
G-5
H-5
I-5
J-5
June
A-6
B-6
C-6
D-6
E-6
F-6
G-6
H-6
I-6
J-6
July
A-7
B-7
C-7
D-7
E-7
F-7
G-7
H-7
I-7
J-7
August
A-8
B-8
C-8
D-8
E-8
F-8
G-8
H-8
I-8
J-8
September
A-9
B-9
C-9
D-9
E-9
F-9
G-9
H-9
I-9
J-9
October
A-10
B-10
C-10
D-10
E-10
F-10
G-10
H-10
I-10
J-10
November
A-11
B-11
C-11
D-11
E-11
F-11
G-11
H-11
I-11
J-11
December
A-12
B-12
C-12
D-12
E-12
F-12
G-12
H-12
I-12
J-12
 
Year/Month
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
January or 1st Qtr
K-1
L-1
M-1
N-1
O-1
P-1
Q-1
R-1
S-1
T-1
February or 2nd Qtr
K-2
L-2
M-2
N-2
O-2
P-2
Q-2
R-2
S-2
T-2
March or 3rd Qtr
K-3
L-3
M-3
N-3
O-3
P-3
Q-3
R-3
S-3
T-3
April or 4th Qtr
K-4
L-4
M-4
N-4
O-4
P-4
Q-4
R-4
S-4
T-4
May
K-5
L-5
M-5
N-5
O-5
P-5
Q-5
R-5
S-5
T-5
June
K-6
L-6
M-6
N-6
O-6
P-6
Q-6
R-6
S-6
T-6
July
K-7
L-7
M-7
N-7
O-7
P-7
Q-7
R-7
S-7
T-7
August
K-8
L-8
M-8
N-8
O-8
P-8
Q-8
R-8
S-8
T-8
September
K-9
L-9
M-9
N-9
O-9
P-9
Q-9
R-9
S-9
T-9
October
K-10
L-10
M-10
N-10
O-10
P-10
Q-10
R-10
S-10
T-10
November
K-11
L-11
M-11
N-11
O-11
P-11
Q-11
R-11
S-11
T-11
December
K-12
L-12
M-12
N-12
O-12
P-12
Q-12
R-12
S-12
T-12
 
Year/Month
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
January or 1st Qtr
U-1
V-1
W-1
X-1
Y-1
Z-1
A-1
B-1
C-1
D-1
February or 2nd Qtr
U-2
V-2
W-2
X-2
Y-2
Z-2
A-2
B-2
C-2
D-2
March or 3rd Qtr
U-3
V-3
W-3
X-3
Y-3
Z-3
A-3
B-3
C-3
D-3
April or 4th Qtr
U-4
V-4
W-4
X-4
Y-4
Z-4
A-4
B-4
C-4
D-4
May
U-5
V-5
W-5
X-5
Y-5
Z-5
A-5
B-5
C-5
D-5
June
U-6
V-6
W-6
X-6
Y-6
Z-6
A-6
B-6
C-6
D-6
July
U-7
V-7
W-7
X-7
Y-7
Z-7
A-7
B-7
C-7
D-7
August
U-8
V-8
W-8
X-8
Y-8
Z-8
A-8
B-8
C-8
D-8
September
U-9
V-9
W-9
X-9
Y-9
Z-9
A-9
B-9
C-9
D-9
October
U-10
V-10
W-10
X-10
Y-10
Z-10
A-10
B-10
C-10
D-10
November
U-11
V-11
W-11
X-11
Y-11
Z-11
A-11
B-11
C-11
D-11
December
U-12
V-12
W-12
X-12
Y-12
Z-12
A-12
B-12
C-12
D-12
 
Year/Month
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
January or 1st Qtr
E-1
F-1
G-1
H-1
I-1
J-1
K-1
L-1
M-1
N-1
February or 2nd Qtr
E-2
F-2
G-2
H-2
I-2
J-2
K-2
L-2
M-2
N-2
March or 3rd Qtr
E-3
F-3
G-3
H-3
I-3
J-3
K-3
L-3
M-3
N-3
April or 4th Qtr
E-4
F-4
G-4
H-4
I-4
J-4
K-4
L-4
M-4
N-4
May
E-5
F-5
G-5
H-5
I-5
J-5
K-5
L-5
M-5
N-5
June
E-6
F-6
G-6
H-6
I-6
J-6
K-6
L-6
M-6
N-6
July
E-7
F-7
G-7
H-7
I-7
J-7
K-7
L-7
M-7
N-7
August
E-8
F-8
G-8
H-8
I-8
J-8
K-8
L-8
M-8
N-8
September
E-9
F-9
G-9
H-9
I-9
J-9
K-9
L-9
M-9
N-9
October
E-10
F-10
G-10
H-10
I-10
J-10
K-10
L-10
M-10
N-10
November
E-11
F-11
G-11
H-11
I-11
J-11
K-11
L-11
M-11
N-11
December
E-12
F-12
G-12
H-12
I-12
J-12
K-12
L-12
M-12
N-12
 
Year/Month
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
January or 1st Qtr
O-1
P-1
Q-1
R-1
S-1
T-1
U-1
V-1
W-1
X-1
February or 2nd Qtr
O-2
P-2
Q-2
R-2
S-2
T-2
U-2
V-2
W-2
X-2
March or 3rd Qtr
O-3
P-3
Q-3
R-3
S-3
T-3
U-3
V-3
W-3
X-3
April or 4th Qtr
O-4
P-4
Q-4
R-4
S-4
T-4
U-4
V-4
W-4
X-4
May
O-5
P-5
Q-5
R-5
S-5
T-5
U-5
V-5
W-5
X-5
June
O-6
P-6
Q-6
R-6
S-6
T-6
U-6
V-6
W-6
X-6
July
O-7
P-7
Q-7
R-7
S-7
T-7
U-7
V-7
W-7
X-7
August
O-8
P-8
Q-8
R-8
S-8
T-8
U-8
V-8
W-8
X-8
September
O-9
P-9
Q-9
R-9
S-9
T-9
U-9
V-9
W-9
X-9
October
O-10
P-10
Q-10
R-10
S-10
T-10
U-10
V-10
W-10
X-10
November
O-11
P-11
Q-11
R-11
S-11
T-11
U-11
V-11
W-11
X-11
December
O-12
P-12
Q-12
R-12
S-12
T-12
U-12
V-12
W-12
X-12
 
Year/Month
1965
1966
1967
1968
1969
  
January or 1st Qtr
Y-1
Z-1
Unknown
Unknown
Unknown
February or 2nd Qtr
Y-2
Z-2
Unknown
Unknown
Unknown
March or 3rd Qtr
Y-3
Z-3
Unknown
Unknown
Unknown
April or 4th Qtr
Y-4
Z-4
Unknown
Unknown
Unknown
May
Y-5
Z-5
Unknown
Unknown
Unknown
June
Y-6
Z-6
Unknown
Unknown
Unknown
July
Y-7
Z-7
Unknown
Unknown
Unknown
August
Y-8
Z-8
Unknown
Unknown
Unknown
September
Y-9
Z-9
Unknown
Unknown
Unknown
October
Y-10
Z-10
Unknown
Unknown
Unknown
November
Y-11
Z-11
Unknown
Unknown
Unknown
December
Y-12
Z-12
Unknown
Unknown
Unknown

Notes: Date code may or may not contain a (dash).