On bug 11046 I proposed to sort e.g. 19xx with 1900. This relates to the kohafield copyrightdate used to sort lists and in reports. For search results, the sort on publication date depends on pubdate as indexed by Zebra. If we add uncertain years like 19xx or better 19uu in the MARC21 008, they will be sorted after 1999 (current situation). We could add a "fix_008" in rebuild_zebra (just as a few other fixes already there) and replace 19uu by 1900 when indexing in order to get 19xx sorted with 1900. What do you think ?
It's a hard one, I wonder how other systems might handle that. My initial feeling is that beginning (1900) seems better than end (1999) - but others might disagree. From the documentatoin: https://www.loc.gov/marc/bibliographic/bd008a.html Determination of dates for 008/07-10 is made concurrently with the choice of code for 008/06. See the section above on 008/06 for examples and input conventions related to coded date information. The use of fill characters in 008/07-10, although possible, is discouraged since the data in Date 1 is used for retrieval and duplicate detection in many systems. When fill is used in 008/07-10, all four positions must contain the fill character.
(In reply to Katrin Fischer from comment #1) > https://www.loc.gov/marc/bibliographic/bd008a.html From the same page: 008/06 s 008/07-10 198u 008/11-14 #### 260 ##$aNew York :$bHaworth,$c[198-] 008/06 s 008/07-10 19uu 008/11-14 #### The character 'u' should normally be used for unknown years.
Adding a See also to 24674 (about copyrightdate field) while this report deals with 008.