- Year - The date of publication. Dates are in the form YYYY-MM-DD, where month and day are filled in if known, otherwise they have the value 00. Under certain circumstances, it is allowable to use a date of 0000-00-00, which means that the publication date is unknown. Examples:
1956-00-00
1956-11-00
1956-11-26
- 8888-88-88 means that the book has been announced but not published and is reserved for well known examples like Last Dangerous Visions.
- For books, to identify the year, try to spot a statement (often on the verso of the title page) that says something like "Published in June 2001"; the copyright date is often misleading, since works can be reprinted. Look out for signs that this is a reprint; indications often include a series of numbers (e.g. "3 4 5 6 7 8 9") at the bottom of the verso of the title page; this particular string indicates that this is a third printing. If you know you are holding a reprint, and there is no way to date that particular publication, leave the year field as 0000-00-00. Note that we are interested in recording each different reprint of a publication, since there can be some significant differences between them, such as cover art, or price.
- For magazines, the month on the cover is rarely the month of actual publication, so by convention the year is given but the month and day are not. Thus the July 1957 issue of New Worlds would be given a year of "1957-00-00". If a magazine date spans a year boundary, such as a December-January bimonthly issue, use the later year.
- If you use a secondary source, such as a bibliography or sf encyclopedia, to find dates, make sure that you note the source of the information on the publication's bibliography wiki page.
- Note also that the publication date does not always perfectly match the calendar date. For example, a January issue of a magazine is usually available in December of the previous year, and often earlier than that. Books with a January publication date may often be bought in the closing weeks of the prior year; they will show the later year's copyright date, even though that year has not yet started. In these cases, the convention is to use the official publication date rather than to try to identify when a book actually first became available. If there is a large discrepancy -- for example if a book was printed but unexpectedly delayed before release -- then this can be noted in the notes field.