std.datetime

[drug via Digitalmars-d-learn]

10.02.2017 14:15, drug пишет:
> unittest
> {
>     import std.datetime : SysTime, UTC;
>
>     {
>         auto st = SysTime();
>         st.timezone(UTC());
>
>         long date  = st.fromISOExtString("2017-02-10T00:00:00Z").stdTime,
>             time_of_day =
> st.fromISOExtString("0000-01-01T23:59:50Z").stdTime,
>             timestamp   =
> st.fromISOExtString("0000-01-01T23:59:55Z").stdTime;
>
>         import std.stdio;
>         st.stdTime(date);
>         writeln(st);
>         st.stdTime(timestamp);
>         writeln(st);
>         st.stdTime(date+timestamp);
>         writeln(st);
>     }
> }
>
> prints
> ```
> 2017-Feb-10 00:00:00Z
> 0000-Jan-01 23:59:55Z
> 2016-Feb-10 23:59:55Z
> ```
> I expect
> ```
> 2017-Feb-10 00:00:00Z
> 0000-Jan-01 23:59:55Z
> 2017-Feb-10 23:59:55Z
> ```
>
> Why does it decrement years? What do I do wrong?
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.