BibLaTeX seasons cause exception on import and export

[distressingly]

JabRef version

Latest development branch build (please note build date below)

Operating system

Windows

Details on version and operating system

Windows 11 24H2 / JabRef 6.0-alpha.65

Checked with the latest development build (copy version output from About dialog)

• I made a backup of my libraries before testing the latest development version.
• I have tested the latest development version and the problem persists

Steps to reproduce the behaviour

1. Import an entry with date = {1991-21}

Appendix

BibLaTeX allows seasons following ISO 8601, which are encoded by using 21–24 in the month field.

java.time.DateTimeException: Invalid value for MonthOfYear (valid values 1 - 12): 21

[urlyy]

@koppor I noticed that your handling of date(format and parse) in biblatex seems to be implemented without relying on third-party libraries, which might lead to some oversights in these standards.

Since accessing ISO 8601 requires payment, I referred to these four documents :

• https://ftp.kddilabs.jp/CTAN/macros/latex/contrib/biblatex/doc/biblatex.pdf (It seems that I can't find any handling of the "season" in the "date" field. There is only the "issue" field and the deprecated "season" field. But as shown in the latex code on overleaf , this is actually implemented.)
• https://en.wikipedia.org/wiki/ISO_8601
  
• https://www.loc.gov/standards/datetime/background.html and https://www.loc.gov/standards/datetime/edtf.html
  

So I confirmed that biblatex does indeed have specific support for seasons. However, in jabref code, the second part of date is recognized as the month. And because it does not conform to the range of months, an exception is thrown.

I am going to participate in this year's GSoC and am looking for a small issue to familiarize myself with JabRef. But first, I'd like to ask whether you think this issue needs to be addressed.

[koppor]

I am going to participate in this year's GSoC and am looking for a small issue to familiarize myself with JabRef. But first, I'd like to ask whether you think this issue needs to be addressed.

Yes, please do so. The issue was risen by a GitHub user seeming non-fake and your screenshot shows that is a valid value.

[Siedlerchr]

Still wtf for me, who to the hell comes up with such ideas in a Standard to abuse the month field o.O

[urlyy]

/assign-me

[github-actions]

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[distressingly]

@koppor I noticed that your handling of date(format and parse) in biblatex seems to be implemented without relying on third-party libraries, which might lead to some oversights in these standards.

Since accessing ISO 8601 requires payment, I referred to these four documents :

• https://ftp.kddilabs.jp/CTAN/macros/latex/contrib/biblatex/doc/biblatex.pdf (It seems that I can't find any handling of the "season" in the "date" field. There is only the "issue" field and the deprecated "season" field. But as shown in the latex code on overleaf , this is actually implemented.)
• https://en.wikipedia.org/wiki/ISO_8601
  
• https://www.loc.gov/standards/datetime/background.html and https://www.loc.gov/standards/datetime/edtf.html
  

So I confirmed that biblatex does indeed have specific support for seasons. However, in jabref code, the second part of date is recognized as the month. And because it does not conform to the range of months, an exception is thrown.

I am going to participate in this year's GSoC and am looking for a small issue to familiarize myself with JabRef. But first, I'd like to ask whether you think this issue needs to be addressed.

The alias in the BibLaTeX documentation is yeardivision, for the record.

[Siedlerchr]

@distressingly Thanks to @urlyy this issue is now fixed in the the latest developement branch

[koppor]

@urlyy Thank you for working on this issue and fixing it fast with high quality! We invite you to choose some other issue. Maybe some "small" from https://github.com/orgs/JabRef/projects/3/views/3? Maybe #12467?

[urlyy]

@koppor Thank you for the invitation!🥹 However, I've been quite busy these days. If I can find some free time in the future, I might come back to work on some issues, and possibly contribute to gsoc as well.

[subhramit]

@koppor Thank you for the invitation!🥹 However, I've been quite busy these days. If I can find some free time in the future, I might come back to work on some issues, and possibly contribute to gsoc as well.

Looking forward to seeing you :)

[koppor]

@koppor Thank you for the invitation!🥹 However, I've been quite busy these days. If I can find some free time in the future, I might come back to work on some issues, and possibly contribute to gsoc as well.

Please ping me on Gitter regarding GSoC so that we can discuss which project might work well for you. Maybe https://github.com/JabRef/jabref/wiki/GSoC-2025-ideas-list#using-postgresql-as-full-backend-for-jabref is an adequate challenge for you :)