Workflow:Validation Error Analysis and Treatment for PDF-hul 133 Invalid date
Workflow Description
The workflow describes the analysis and the fix of a specific instance of a PDF-HUL-133 error. It is a manual workflow. The methodology used here is that introduced in https://hdl.handle.net/2142/121092.
Validation Error
JHOVE v1.30.0RC1 PDF-hul v1.12.5 PDF-HUL-133 Invalid Date. Well-formed, but not valid.
Cross-Check with other Tools
Cross-checked with: pdfcpu v0.6.0dev relaxed mode - no error pdfcpu v0.6.0dev strict mode - no error qpdf v9.1.1 - no error Arlington PDF Model checker by verapdf 1.26.0-RC1 Greenfield Parser: Entry ModDate in DocInfo shall have type Date (1 occurance) Entry CreationDate in DocInfo shall have type Date (1 occurance)
Locate Error in Spec
ISO3200-2:2017 (PDF 2.0 Spec) lists the the Keys CreationDate and ModDate in the Document Info Dictionary as type Date. Section 7.0.4 defines that a date shall be a text string containing no whitespace, of the form: "(D:YYYYMMDDHHmmSSOHH'mm) where: YYYY shall be the year MM shall be the month (01–12) DD shall be the day (01–31) HH shall be the hour (00–23) mm shall be the minute (00–59) SS shall be the second (00–59) O shall be the relationship of local time to Universal Time (UT), and shall be denoted by one of the characters PLUS SIGN (U+002B) (+), HYPHEN-MINUS (U+002D) (-), or LATIN CAPITAL LETTER Z (U+005A) (Z) (see below) HH followed by APOSTROPHE (U+0027) (') shall be the absolute value of the offset from UT in hours (00–23) mm shall be the absolute value of the offset from UT in minutes (00–59)
The prefix D: shall be present, the year field (YYYY) shall be present and all other fields may be present but only if all of their preceding fields are also present. The APOSTROPHE following the hour offset field (HH) shall only be present if the HH field is present. The minute offset field (mm) shall only be present if the APOSTROPHE following the hour offset field (HH) is present. The default values for MM and DD shall be both 01; all other numerical fields shall default to zero values. A PLUS SIGN as the value of the O field signifies that local time is now and later than UT, a HYPHEN-MINUS signifies that local time is earlier than UT, and the LATIN CAPITAL LETTER Z signifies that local time is equal to UT. If no UT information is specified, the relationship of the specified time to UT shall be considered to be GMT. Regardless of whether the time zone is specified, the rest of the date shall be specified in local time."
The specification further notes that "versions up to and including 1.7 defined a date string to include a terminating apostrophe. PDF processors are recommended to accept date strings that still follow that convention".
Locate Error in File
Offset given by JHOVE only points to place where reference was used in GoTo destination. The reader tries to resolved the named destination used in the GoTo action via the name tree. Here the object is missing and replaced by "Null".
(Rechte_von_Eltern_in_der_Kita_2018_V7_bf.indd:.45593:62)[null/Fit ]
Match?
Yes.
Fixable?
Yes.
Fix
Find location by checking page object the wrong destination is used on. With Adobe Acrobat Pro's "Edit Link" option, the erronous link can be removed and replaced by a correct one, if known.
Check
Re-validated file with JHOVE: now well-formed and valid. Link is now actionable.
Success?
Yes.
