BC dates have wrong datatype, are missing the negative sign, or are missing

I have an old partial DBpedia persons dump including negative (BC) birth and death dates such as this:

Brutus_of_Troy deathDate "-1125-1-1"^^xsd:date .

However when checking those persons on current DBpedia, I got different results when checking some of them:

  • dbpedia:Brutus_of_Troy does not have a death date anymore (“-1125-1-1”^^xsd:date before)
  • dbpedia:Bryson_of_Heraclea used to have a death date of -400-1-1"^^xsd:date ., also does not have one anymore
  • dbpedia:Empress_Dowager_Bo used to have death date “-155-1-1”^^xsd:date, now it’s “155”^^xsd:integer
  • Yāska had dbo:birthDate -500-1-1"^^xsd:date, on current DBpedia the value is is 7 (xsd:integer) (wrong datatype, missing sign, wrong magnitude as she is estimated to have been living somewhere between 500 and 700 BC)

P.S.: Error while posting, had to remove the links because only 2 links are allowed.
P.P.S.: According to ISO 8601 - Wikipedia, years before 1583 are a nonstandard expansion, however they should be valid xsd:date values.

In cases where the datatype has changed from xsd:date to xsd:integer, or if there are wrong datatype values, you can try to update your dataset accordingly. If a birth or death date is represented as an integer when it should be a crm data enrichment, you may need to correct the datatype. If certain individuals no longer have birth or death dates in the current DBpedia dataset, it could be due to updates, corrections, or changes in the available information. For Yāska, it appears that there are issues with the date format, missing sign, and wrong magnitude. You can update the dataset to reflect the correct date and datatype based on the available information.