What is the meaning of year 0, and negative years

In dateValue and other places ABNF allows year zero (or negative).

Now with OData V4 there is no specific reference to XML Schema Part 2 DataTypes (Second Edition) although OData 3 spec did have a reference to that document for dateTimeOffsetLiteral, so perhaps there is an unwritten understanding that OData lexical representations match those defined in XML Schema Part 2 Datatypes (Second Edition).

In any case, see https://www.w3.org/TR/xmlschema-2/#year-zero

Key questions: (see the linked XML Schema section)

(1) Is year 0 valid in OData Date/DateTimeXXX values (including Edm.String with Core.DateTime annotation in 4.01)? If so, what does it mean? (e.g. 1 BCE)

(2) What is the interpretation of negative years in OData Date/DateTimeXXX values? Is year -1 equivalent to 1 BCE, or to 2 BCE?