Re: [icu-support] DateTime formatting issues with pre-Gregorian dates

[Jamie D. <jam...@gm...>]

FWIW, before asking here I did try and search through the mailing list, and
this post from 2006 kept cropping up:
https://sourceforge.net/p/icu/mailman/message/12529106/

This is strikingly similar to what I'm seeing (1st Jan 0001 is 2 days off -
I get 3rd Jan 0001), but given this is from 2006, surely it's been fixed by
now?

-Jamie.

On 27 July 2016 at 23:40, Jamie Dale <jam...@gm...> wrote:

> Hey all,
>
> I'm investigating an issue where pre-Gregorian dates are failing to format
> correctly with icu::DateFormat.
>
> We're using ICU 53, and our internal concept of time is ticks of 0.1
> microseconds since 1st January 0001 - we convert this to a UNIX timestamp
> and multiply by U_MILLIS_PER_SECOND before passing it to ICU as a UDate.
>
> At first I thought this might be due to the Gregorian switch-over, so I
> tried constructing my own icu::GregorianCalendar, setting the Gregorian
> change date to 1st January 0001, and then letting the icu::DateFormat adopt
> that as its calendar, however it didn't seem to make any difference (my
> calendar reports U_USING_FALLBACK_WARNING when being constructed... I'm not
> sure why).
>
> I'm wondering if anyone else has seen this issue, or whether anyone has
> any advice?
>
> Thanks,
> Jamie.
>