0xx Fields

Contents   Fixed field   Access points   0xx   1xx   2xx   3xx   4xx   5xx   6xx   7xx   8xx   9xx   Control subfields

045  Time Period of Content (NR)

Record Type

BIB

Input Standards

Field (Full/Minimal)
Optional/Optional
1st Indicator  Type of time period in subfield ǂb or subfield ǂc
blank character Subfield ǂb or ǂc not present
0 Single date/time
1 Multiple single dates/times
2 Range of dates/times
2nd Indicator  Undefined
blank character Undefined
Subfields (R=Repeatable  NR=Nonrepeatable) Input Standards (Full/Minimal)
ǂa Time period code (R) Required if applicable/Required if applicable
ǂb Formatted 9999 B.C. through C.E. time period (R) Required if applicable/Required if applicable
ǂc Formatted pre-9999 B.C. time period (R) Required if applicable/Required if applicable
ǂ6 Linkage (NR) System supplied/System supplied
ǂ8 Field link and sequence number (R) Optional/Optional

Definition

A time period code and/or a formatted time period associated with the resource described in the bibliographic record.

Guidelines

Determine the appropriate values by examining the resource. Use the primary source of bibliographic information (e.g., title page), prefatory material, table of contents, and summary statements. In addition, subject headings may indicate chronological coverage. Be as specific as possible.

The nature of the chronological content varies with the resource type as described below:

BKS, CNR

Indicates the time period depicted by the content of the resource.

045     at-t-
045 2   ǂb d1500 ǂb d1599
[Documentary collection for the period 1500-1599]

Do not use for any resource for which a chronological approach would not be a logical or common approach to the subject matter. Do not use for the following:

  • Biography, unless a time period is specified on the piece or in a subject heading
  • Collections or anthologies of literature, unless they indicate a clearly delineated time period
  • Comprehensive histories of a subject or a country that cover more than 500 years
  • Dictionaries, encyclopedias, glossaries, catalogs, and gazetteers intended to be nonhistorical in approach
  • Genealogies and family histories
  • Handbooks, manuals, and "how-to" books
COM

Indicates the time period covered by the data in the file.

045     x5x6
[Data file containing statistics for the period 1950-1960]
MAP

Indicates the time period associated with the place shown in the resource, that is, the situation date. A currently prepared map of Rome in 50 B.C. would be coded for the B.C. date. A remote-sensing map which depicts the time the satellite recorded the image would be coded for that time.

045 2   ǂb c500 ǂb c265
264 1   Chicago : ǂb Denoyer-Geppert Company, ǂc 1970.
[Currently prepared map of ancient Italy for the period 500 B.C. to 265 B.C.]
045 0   ǂb d1978
264 1   Reston, Va. : ǂb Interior--Geological Survey, ǂc 1983.
[Remote-sensing map depicting the time the satellite recorded the image in 1978]
MIX

Indicates the time period covered by the collection.

045     t1w2
[Documentary collection for the period 1511-1821]
SCO, REC

Indicates the time period of the composition, and will usually relate to the date of the composition. If the precise date of composition cannot be determined, an approximate date (or range of dates) or the dates of the composer are used.

045 0   ǂb d1808
[Symphony composed in 1808]
VIS

In motion pictures and videorecordings, field 045 indicates the time period associated with the content of the moving image resource.

In two-dimensional nonprojected graphic representations, field 045 indicates the time period associated with the content of the graphic.

In artifacts, field 045 indicates the time period associated with the content of the artifact.

In naturally occuring objects, field 045 indicates the time period associated in which the object originated.

045 2   ǂb d1900 ǂb d1986
[Videorecording documentary of the history of the brewing industry in Wisconsin for the period of 1900-1986]
045     w7x3
[Collection of photographs from 1870-1930]
045     x2x3
[Model of an automobile repair shop of the 1920-1930 period]

1st Indicator

Type of time period in subfield ǂb or subfield ǂc. A value that indicates whether subfield ǂb or subfield ǂc is present and when present, the type of time period contained. The values distinguish among a single date/time, multiple single dates/times, and a range of dates/times.

 
blank character

Subfield ǂb or ǂc not present. Neither subfield ǂb nor subfield ǂc is present.

045     a0d6
651   0 Egypt ǂx Economic conditions ǂy To 332 B.C.
 
0

Single date/time. Subfield ǂb or subfield ǂc is present, and contains a single date/time.

045 0   ǂc 2500000000
650   0 Lunar petrology
 
1

Multiple single dates/times. Multiple subfield ǂb and/or subfield ǂc are present and each contains a date/time. A range of dates/times is identified by value 2.

045 1   ǂb d1972 ǂb d1975
[1972 and 1975]
 
2

Range of dates/times. Two subfield ǂb and/or subfield ǂc are present and contain a range of dates/times. Multiple single dates and/or times are identified by value 1.

045 2   ǂb d186405 ǂb d186408
650   0 Shenandoah Valley Campaign, 1864 (May-August)
045 2   ǂc 25000 ǂc 15000
650   0 Aurignacian culture

2nd Indicator

Undefined. The 2nd indicator position is undefined and contains a blank.

blank character

Undefined

Subfields

 
ǂa Time period code

The four-character time period code. The first two characters represent the earliest period covered. The last two represent the latest period covered. If a single two-character code encompasses the entire period, enter the code twice. Use the codes from the table below:

 
B.C. table   C.E. table
Time period Code   Time period Code
before 2999 a0   1-99 e
2999-2900 b0   100-199 f
2899-2800 b1   200-299 g
2799-2700 b2   300-399 h
2699-2600 b3   400-499 i
2599-2500 b4   500-599 j
2499-2400 b5   600-699 k
2399-2300 b6   700-799 l
2299-2200 b7   800-899 m
2199-2100 b8   900-999 n
2099-2000 b9   1000-1099 o
1999-1900 c0   1100-1199 p
1899-1800 c1   1200-1299 q
1799-1700 c2   1300-1399 r
1699-1600 c3   1400-1499 s
1599-1500 c4   1500-1599 t
1499-1400 c5   1600-1699 u
1399-1300 c6   1700-1799 v
1299-1200 c7   1800-1899 w
1199-1100 c8   1900-1999 x
1099-1000 c9   2000-2099 y
999-900 d0   (Add 0, 1, 2 ... 9 for the decade)
899-800 d1      
799-700 d2      
699-600 d3      
599-500 d4      
499-400 d5      
399-300 d6      
299-200 d7      
199-100 d8      
99-1 d9      

Examples
Period covered Time period code
423 B.C.-390 B.C. d5d6
To 300 B.C. a0d6
42 B.C.-A.D. 37 d9e3
1066-1328 o6r2
12-14th centuries p-r-
1740-1840 v4w4
1828-1859 w2w5
20th century x-x-
Compare 1st century A.D. and 20th century e-e- ǂa x-x-
Collected scores of George Gershwin's musical comedies x2x3
 
  • B.C. (Before Common Era) dates. Use a lowercase alphabetic character to represent the millennium and a digit to represent the century. If the century is not known, enter a hyphen instead of a digit.

    045     a-c-
    650   0 Bronze age
    [3000–100 B.C.]
    045     c4c6
    651   0 Egypt ǂx History ǂy Eighteenth dynasty, ca. 1570-1320 B.C.
    045     d7d9
    651   0 Rome ǂx History ǂy Republic, 265-30 B.C.
  • C.E. (Common Era) dates. Use a lowercase alphabetic character to represent the century and a digit to represent the decade. If the decade is not known, enter a hyphen instead of a digit. If more than one time period code applies, enter each in a separate subfield ǂa.

    045     x8x8
    650   0 Bhopal Union Carbide Plant Disaster, Bhopal, India, 1984
    045     t-v-
    650   0 Catalan literature ǂy 16th-18th centuries
    045     x-x-
    650   0 Civilization, Modern ǂy 20th century
    045     y-y-
    650   0 Twenty-first century ǂx Forecasts
    045     o6s8
    651   0 Great Britain ǂx History ǂy Medieval period, 1066-1485
    045     d8h2
    651   0 Greece ǂx History ǂy 146 B.C.-323 A.D.
ǂb Formatted 9999 B.C. through C.E. time period

A specific time period formatted as yyyymmddhh preceded by code c for B.C. or code d for C.E. The era and year are required. The month, day, and hour (based on the 24-hour clock) are optional.

Enter only known elements with a five-character minimum. Use subfield ǂa if you cannot determine the first five characters.

Enter each 9999 B.C. through C.E. time period associated with the heading in a separate subfield ǂb.

045 2   d7n6 ǂb c0221 ǂb d0960
651   0 China ǂx History ǂy 221 B.C.-960 A.D.
045 2   ǂb d1791 ǂb d1797
651   0 France ǂx History ǂy Revolution, 1791-1797
045 0   ǂb d19360226
651   0 Japan ǂx History ǂy February Incident, 1936 (February 26)
ǂc Formatted pre-9999 B.C. time period

A formatted time period consisting of as many numeric characters as are needed to represent the number of years B.C. Enter each pre-9999 B.C. time period associated with the heading in a separate subfield.

045 2   ǂc 225000000 ǂc 70000000
650   0 Geology, Stratigraphic ǂy Mesozoic
ǂ6 Linkage

Data that link fields when non-Latin script is entered. This subfield is system supplied and does not appear in OCLC online displays. Do not add subfield ǂ6. For more information about subfield ǂ6, see Control Subfields.

ǂ8 Field link and sequence number

For information about subfield ǂ8, see Control Subfields.

Indexing

Field 045 is not indexed.

MARC 21

For more information, including content designator history, see MARC 21 Format for Bibliographic Data, field 045.

This page last revised: October 22, 2020