On Fri, 17 Jan 2020 at 17:52, Bruce Momjian <br...@momjian.us> wrote:
> I assume there is enough agreement that decades start on 20X0 that we > don't need to document that Postgres does that. > I think the inconsistency between years, decades, centuries, and millenia is worthy of documentation. In fact, it already is for EXTRACT: https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT It describes decade as "The year field divided by 10", whereas for century and millennium it refers to centuries and millennia beginning in '01 years. I think if I were designing EXTRACT I would probably have decades follow the pattern of century and millennium, mostly because if somebody wants year / 10 they can just write that. But I am, to say the least, not proposing any modifications to this particular API, for multiple reasons which I'm sure almost any reader of this list will agree with.
