BibEntry assumes package dates are in "dd/mm/yyyy" format

[stertooy]

In the following piece of code, the BibEntry function assumes the Date field of a package info record is in the "dd/mm/yyyy"-format (or dd@mm@yyyy with any choice of separator @ really).

gap/lib/package.gi

Lines 2936 to 2948 in 0d29d4b

	if IsBound( pkginfo.Date ) and IsDenseList( pkginfo.Date )
	and Length( pkginfo.Date ) = 10 then
	if Int( pkginfo.Date{ [ 4, 5 ] } ) in [ 1 .. 12 ] then
	Append( entry, Concatenation(
	" <month>", NameMonth[ Int( pkginfo.Date{ [ 4, 5 ] } ) ],
	"</month>\n",
	" <year>", pkginfo.Date{ [ 7 .. 10 ] }, "</year>\n" ) );
	else
	Append( entry, Concatenation(
	" <month>", pkginfo.Date{ [ 4, 5 ] }, "</month>\n",
	" <year>", pkginfo.Date{ [ 7 .. 10 ] }, "</year>\n" ) );
	fi;
	fi;

However, I think the current recommendation is for dates to be in the "yyyy-mm-dd" format. This causes trouble for GitHubPagesForGAP, which relies on BibEntry to get its information for citing a package - see e.g. the GitHub page for the Example package, which has:

[NGK20]
Nickel, W., Gamble, G. and Konovalov, O.,
Example,
Example/Template of a GAP Package,
Version 4.4.0 (1-20) (GAP package),
https://gap-packages.github.io/example.

Here, the citekey should be NGK24 and the year should be 2024, of course. The mistakes stem from BibEntry assuming that the last 4 characters of the string 2024-11-20 represent the year. By contrast, in the same function, the date of GAP itself is assumed to be in the "yyyy-mm-dd"-format:

gap/lib/package.gi

Lines 2880 to 2891 in 0d29d4b

	val:= SplitString( GAPInfo.Date, "-" );
	if Length( val ) = 3 then
	if Int( val[2] ) in [ 1 .. 12 ] then
	val:= Concatenation( " <month>", NameMonth[ Int( val[2] ) ],
	"</month>\n <year>", val[1], "</year>\n" );
	else
	val:= Concatenation( " <month>", val[2],
	"</month>\n <year>", val[1], "</year>\n" );
	fi;
	else
	val:= "";
	fi;

What may complicate things, is that when GAP reads package metadata on startup, it seems to automatically convert dates to "dd/mm/year"-format before storing it in GAPInfo.PackagesInfo, whereas no such conversion happens when calling GAPInfo.PackageInfoCurrent. If I am working in Example's base directory:

[...]/example$ echo "Print(GAPInfo.PackagesInfo.example[1].Date,\"\n\");QuitGap();" | gap -A -q 
20/11/2024
[...]/example$ echo "Read(\"PackageInfo.g\");Print(GAPInfo.PackageInfoCurrent.Date,\"\n\");QuitGap();" | gap -A -q 
2024-11-20