std.datetime

[Jonathan M Davis via Digitalmars-d-learn]

On Friday, February 10, 2017 14:35:28 drug via Digitalmars-d-learn wrote:
> I found error - years should start from 1, not 0.
> But if months or days start from 0 std.datetime throws exception and
> don't for years - it isn't clear that zero year is negative one (in that
> mean that stdTime for '0000' years will be negative.

As the documentation states in multiple places, std.datetime follows ISO
8601, which uses the Proleptic Gregorian Calendar, and that specifies that
the year 0 is equivalent to what you would normall consider to be 1 B.C.
And that's part of the spec for the ISO extended format that
fromISOExtString uses.

Now, while it is mentioned in multiple places that std.datetime follows ISO
8601 and that it follows the Proleptic Gregorian Calender (even providing a
link to wikipedia), it does look like it fails to specifically mention that
on the primary ddoc comment of SysTime. So, that should be improved.
However, the documentation for SysTime.year does state that positive years
are A.D., whereas non-positive are B.C. So, the information is there, even
without having to look up the Proleptic Gregorian Calender or ISO 8601.

What would have made it clearer for you?

- Jonathan M Davis