Hi Lydia, I think the problem is that instead of a semantic comparison, Wikibase does a pure string comparison to check if two timestamps are equal. I changed the primary sources tool on the weekend because there was a bug in the serialization according to the TSV format specification (it failed a roundtrip serialize-parse test), which says the year in a timestamp is 11 digits, 0-padded if necessary (i.e. +00000001947 instead of +1947). This might have broken the comparison. The weird thing is that later (probably when storing the value in the database), Wikibase does the right thing (i.e. parses the year even including leading 0's). So I guess the comparison is happening before that. I can fix that by rolling back my change that introduced the 0-padding, but the consequence is that it will no longer follow the definition at http://tools.wmflabs.org/wikidata-todo/quick_statements.php . Or we change the Javascript frontend part to eliminate all padding 0 before sending the timestamp to the API. But since 0-padding is semantically valid for numbers, I'd prefer to have a look in the Wikibase backend. There might be other situations affected by string comparison issues. Cheers, Sebastian On Wed, Apr 6, 2016 at 1:24 PM Lydia Pintscher <Lydia.Pintscher(a)wikimedia.de> wrote:

Hi, the "definition" at Magnus' http://tools.wmflabs.org/wikidata-todo/quick_statements.php is outdated. Magnus, can you please remove the leading zeros from the year? Padding years to 11 digits is not done any more. For a while there was no padding at all in the backend, while some documentation talked about 16 digits and the frontend still padded to 11 digits. All at the same time. :-( We fixed this about a year ago and decided to always pad years to 4 digits because this minimizes storage space while being the most convenient strategy for users. Best Thiemo

Is this answer from TPT related? https://github.com/google/primarysources/issues/90#issuecomment-206256966. Sorry, I am at a multi-day event this week and am a bit behind on emails. If it is, I am happy to quickly merge a pull request if anyone creates it :-) -- Dr. Thomas Steiner, Employee (http://blog.tomayac.com, https://twitter.com/tomayac) Google Germany GmbH, ABC-Str. 19, 20354 Hamburg, Germany Managing Directors: Matthew Scott Sucherman, Paul Terence Manicle Registration office and registration number: Hamburg, HRB 86891