4. Dates

If both class number and cutter(s) are the same, then the order is determined by the date. If a call number lacks a date, the call number without the date precedes the first call number with a date.

Note that:

call numbers for serials and classed together monographic series are never assigned dates
call numbers for classed together multipart monographs are assigned the date of the earliest volume in hand at the time of cataloging (for copy cataloging, use the date supplied in the call number if it is earlier than the date of the earliest volume in hand at the time of cataloging)
if the main entry is a conference with a date subfield, the call number date should match the date of the conference, not the date of publication (if the conference is not the main entry, the call number should match the date of publication)
generally follow SCM Shelflisting G140 in relating the call number date to the imprint date. However, follow local practice for capitalization (see 5. Workletters [1] following).

Date	Call number date
1976?	use 1976
ca. 1976	use 1976
1981, c1980	use 1981
1971, c1972	use 1972
1979 [i.e. 1978]	use 1978
1962 or 1963	use 1962
1969 (1973 printing)	1969
1980 printing, c1957	use 1957
1979 [distributed 1980]	use 1979
1979-1981	use 1979
between 1977 and 1980	use 1977
1978/79 [i.e. 1978 or 1979]	use 1978
1977 (cover 1978)	use 1978
197-?	use 1970z [if corporate body use 1970]
19--	use 1900z [if corporate body use 1900]
19--?	use 1900z [if corporate body use 1900]

Less common situations where a date is not used:

◦ After the designations Suppl and Index. However, the edition to which the volume is the supplement or call number may have a date, in which case the date of the edition will precede the designation:

.C67 1977
.C67 1977 Suppl.
.C67 1977 Suppl. 2

◦ Loose-leaf materials
◦ Legal publications where the final cutter is selected from a span based on dates