Describe the bug
Crating a Poco::Timestamp from Poco::DateTime and using Poco::DateTimeFormatter::format() creates invalid ISODate with negative hour, minute and second values for timestamps before October 15, 1582.

To Reproduce

std::string orig("1582-10-14T00:00:01Z");
Poco::DateTime dateTime;
int tzd;
Poco::DateTimeParser::tryParse(Poco::DateTimeFormat::ISO8601_FRAC_FORMAT, orig, dateTime, tzd);

const auto pts = dateTime.timestamp();
auto fmt = Poco::DateTimeFormatter::format(pts, Poco::DateTimeFormat::ISO8601_FRAC_FORMAT);

Expected behavior
Expected result is "1582-10-14T00:00:01.000000Z" instead of "1582-10-14T-23:-59:-59.000000Z" which is invalid ISODate.

Logs
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Screenshots
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Please add relevant environment information:

• OS Ubuntu 20.04
• POCO 1.10.1

Additional context
I'm not sure if this is a bug or limitation of allowed Poco::Timestamp date range. Interesting is that the year, month and date are properly formatted from Poco::Timestamp value and just the hour, minute and second become negative.