Currently, on Windows, you get the following error if you pass a negative timestamp:

(arrow) C:\Users\Chris>python
Python 3.7.4 (tags/v3.7.4:e09359112e, Jul  8 2019, 20:34:20) [MSC v.1916 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import arrow
>>> arrow.get(-15675657)
Traceback (most recent call last):
  File "<stdin>", li

This is related to #410 and #859, we currently only support a limited subset of possible values for RDATE, but we should support all the parameters in RDATE, the grammar for which is set out in RFC 5545:

       rdate      = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF

       rdtparam   = *(
                  ;
                  ; T

Is your feature request related to a problem? Please describe.
If I explicitly say Let's have a meeting at 3pm UTC and UTC is not my time zone, it would be helpful if I and other people in my time zone got the translation. That way I can be sure I chose the right time myself!

(Plus, this also means that when talking about events from UTC logs I can use TZB as a timezone translator! Yay!)

New locale handling is pretty cool, thanks. But I think I found a bug in relativeTime plugin.

So, there are three declensions of nouns in Russian: singular, dual and plural. The library does have h, hh and hhh for all of those (this is the case with other units as well), but it assumes that single-letter format is only used when the value of whatever unit is exactly 1. For example "ча