This field consists of a single-letter date-type, followed by one or two four-digit dates. Most commonly, it will consist of the letter d (monograph, single date of publication) followed by the year of publication.
#0ca d1995
Monograph published in 1995.
#0ca a19849999
Current periodical, first published in 1984.
Any unknown element of the year is expressed with the letter u, for example:
#0ca d193u
| a | currently published serial; date 1: first issue, date 2: 9999 |
| b | dead serial; date 1: first issue, date 2: last issue |
| c | serial of unknown status; date 1: first issue, date 2: blank |
| d | monograph, complete, published within one calendar year; date 1: publication date, date 2: blank |
| e | reproduction; date 1: publication date, date 2: date of original |
| f | monograph, publication date uncertain; date 1: earliest possible date of publication, date 2: latest possible date of publication |
| g | monograph, publication continues for more than a year; date 1: beginning date of publication, date 2: final date, or 9999 if still in progress |
| h | monograph with both actual and copyright date; date 1: publication, date 2: copyright date |
| i | monograph with both issue date and production date (used for films and music when there is a gap between the production of an item and its release; date 1: issue date, date 2: production date |
| j | monograph with detailed date of publication; date 1, year of publication, date 2: month and day, right justified with zero fill - if the day positions are not used, they hold blanks |