Panic in conversion of NaiveDateTime to the local time on Windows

[vvkostenko]

Code like this works fine:

let naivedatetime = NaiveDate::from_ymd_opt(1900, 1, 1)
    .unwrap().and_hms_opt(0, 0, 0)
    .unwrap();

let datetime_from_utc = Local.from_utc_datetime(&naivedatetime);
let datetime_from_local = Local.from_local_datetime(&naivedatetime).unwrap();

But changing of the first line to

let naivedatetime = NaiveDate::from_ymd_opt(1898, 1, 1)
        .unwrap().and_hms_opt(0, 0, 0)
        .unwrap();

causes a panic: thread 'datetime::tests::test_from_naive_date_time_conversions' panicked at 'attempt to subtract with overflow', src\offset\local\windows.rs:223:18

I face this problem on Windows only. So what range of datetime should be supported by functions Local.from_utc_datetime and Local.from_local_datetime on Windows?

[djc]

This looks like a bug. Assuming you're on 0.4.x, the code says:

tm_year: d.year() - 1900,  // this doesn't underflow, we know that d is `NaiveDateTime`.

Which indicates the comment is clearly wrong? This code seems to be using a struct Tm which restricts tm_year to "Years since 1900" which seems just a silly limitation. The Microsoft documentation for the SYSTEMTIME suggests that its wYear supports values "from 1601 through 30827".

So the Windows code here seems pretty broken. Would you be interested in helping to fix it? That would be great.

[vvkostenko]

@djc, sure. I can try to fix it

[pitdicker]

This particular issue was fixed in #992. We still panic on years prior to 1601 however.

Because there are other open issues about that case I am going to close this one. See #651 and #1150.