Publication dates in Librario

Not every work has an exact publication date. An old paperback says only “around 1975”, a multi-volume work appeared from 1973 to 1986, a journal issue came out in spring 2004. Librario takes such dates in the Publication date field and shows them in words: on the publication page, in the search results and in shared links.

The notations follow the open EDTF standard of the Library of Congress. The same notation works for cataloguing and for the Year filter in search.

Notations

The seasons are 21 spring, 22 summer, 23 autumn and 24 winter. Winter runs from December into February of the following year, so Librario shows 2004-24 as “Winter 2004/05”.

A period needs an exact date at both ends. Write 1970/1989 instead of 197X/198X, and leave ~ and ? off the ends.

In the form, you don’t need to know the notation by heart. Date helper… next to the field opens Enter publication date. There you choose Publication date, Date range or Decade or century, and for a publication date also Approximate (circa) or Uncertain (?). Apply writes the notation into the field. Under the field, Librario says in words what the date means, such as “circa 1975”. Type seasons directly, as in the table above.

Librario does not accept years before the Common Era. It also rejects rare EDTF forms such as 1XXX or a mark on the month alone (2004-?06), and lists notations that work.

Approximate and uncertain dates

• ~ approximate: the year is an estimate, for example from the typography or a publisher’s list. Librario shows “circa 1975”.
• ? uncertain: the year is likely but not confirmed. Librario shows “1975 (uncertain)”.
• % both: estimated and not confirmed. Librario shows “circa 1975 (uncertain)”.

These marks change only how the date is shown, not how search finds it: search treats 1975~ like 1975.

How search finds a date

The search results and the publication page show the date in words, such as “1970s” or “1973–1986”. Search counts the earliest day of that date: 1 January 1970 for “1970s”, 1 January 1973 for “1973–1986”. A filter finds the publication when that day falls inside the chosen period. So choose a period that includes the year the date begins with: for a work from the 1970s, drag the left handle to 1970 or earlier.

An open start such as ../1990 has no earliest day, so the end counts instead.

You choose the period in the chart above the Year filter, with a preset period or through Choose period…. Searching for publications shows how. The chart counts each publication in the year search finds it under. If many works are recorded as 197X, the bar for 1970 stands out for that reason.

Two notations exist only in search:

• Several dates: [1667,1668] finds publications from 1667 or 1668. You cannot catalogue “1667 or 1668”. Record the period 1667/1668 instead; search then finds the work through 1667.
• No date: (null) finds publications without a publication date. In Choose period… this is No year specified.

Exports and interfaces

Formats with a plain year field get the earliest possible year: 197X becomes 1970, 19XX 1900, ../1990 1990. This applies to the year in BibTeX, EndNote and the CSV column “Publication year”. The full date sits alongside in the CSV column “Publication date”; BibLaTeX writes dates such as 197X or 1973/1986 in full to the date field. The data model describes what the AI assistant and the REST API return.