# BibLaTeX doesn't print all the information I put in?

I use BibDesk to construct my .bib files. This program gives me some fields to put information, depending on the type of reference (book, article, etc.). However, LaTeX doesn't print all the information I put into the .bib file... e.g.:

\documentclass[12pt]{amsart}
\usepackage[backend=bibtex]{biblatex}
\bibliography{myrefs}

\begin{document}

\printbibliography
\end{document}


with 'myrefs.bib':

@url{gaussianintegrals,
Date-Modified = {2015-12-09 18:26:49 +0000},
Lastchecked = {9-12-2015},
Title = {Gaussian Integrals},
Url = {http://www.umich.edu/~chem461/Gaussian%20Integrals.pdf},


I only get:

Gaussian Integrals. url: http://www.umich.edu/~chem461/Gaussian% 20Integrals.pdf.

How do I get it to also print, for example, the 'last-checked' field?

• You need \addbibresource{myrefs.bib}. See Is there any advantage to using \addbibresource over \bibliography? and biblatex for idiots. – Werner Dec 15 '15 at 20:08
• @Werner Where? In the preamble? This doesn't change anything? Isn't it equivalent to '\bibliography{myrefs}'? – Michael Angelo Dec 15 '15 at 20:11
• Oh, I see. You need to specify how your @url{...} entries are displayed. Fields like Date-Added, Date-Modified and Lastchecked are unknown in terms of the generic placement. – Werner Dec 15 '15 at 20:12
• Normally, you would have e.g. a urldate which specifies the date you accessed the URL. If there is no date, year etc., this will also be used where those are required. What is printed depends on the style and options you use. However, as @Werner says, those are simply not standard fields. You would need to add them and specify suitable formatting etc. These are not standard details included in entries by most bibliographical styles. Are you sure you need this information and that you don't need something more standard instead? – cfr Dec 16 '15 at 2:40
• In biblatex there is no field Lastchecked, you can give this information in the urldate field. Please note that all date fields in biblatex must be given in YYYY-MM-DD format (with leading zeroes). date-added and date-modfied are probably not fields you need to see in the bibliography in your document at all. – moewe Dec 16 '15 at 7:29

Normally, you would have e.g. a urldate field in your .bib entry which specifies the date you accessed the URL. If there is no date, year etc., this will also be used where those are required.

What is printed and in what format it is printed depends on the style and options you use.

However, as Werner said, Date-Added, Date-Modified and Lastchecked are simply not standard .bib fields.

If you especially wished to use these fields, you would need to add them and specify suitable formatting etc. by creating suitable custom commands using the Biblatex interface. That said, these are not standard details included in entries by most bibliographical styles.

Are you sure you need this information and that you don't need something more standard instead? It is common to provide a date of publication and, for URLs, a date accessed. These should be entered as

date = {YYYY-MM-DD},


for the publication date and

urldate = {YYYY-MM-DD},


for the date you accessed the site. As moewe noted, the format is crucial here. These dates must be entered one of the following formats:

• YYYY-MM-DD e.g. 1845-01-23

• YYYY-MM e.g. 1234-05 where no specific date is known

• YYYY e.g. 1066 where the month is also unknown.

Note that the Biber backend is recommended and that some Biblatex features are not available with the BibTeX backend.