Try to use native time zone of Windows

The dateutil implementation fails on Windows for date before epoch.

issue8145
review58541002

doc/usage.rst

@@ -431,11 +431,6 @@ increases if lower case or decreases if upper case:
     - `i`: by one minute
     - `s`: by one second
 
-.. warn::
-    Under Windows, the datetime before 1970 are shown in UTC instead of the
-    local timezone.
-..
-
 Search Widget
 ^^^^^^^^^^^^^
 

tryton/common/common.py

@@ -42,7 +42,6 @@ try:
 except ImportError:
     ssl = None
 from threading import Lock
-import dateutil.tz
 
 from gi.repository import Gdk, GdkPixbuf, GLib, GObject, Gtk
 
@@ -1243,16 +1242,17 @@ def filter_domain(domain):
 
 
 def timezoned_date(date, reverse=False):
-    lzone = dateutil.tz.tzlocal()
-    szone = dateutil.tz.tzutc()
+    try:
+        from dateutil.tz.win import tzwinlocal as tzlocal
+    except ImportError:
+        from dateutil.tz import tzlocal
+    from dateutil.tz import tzutc
+
+    lzone = tzlocal()
+    szone = tzutc()
     if reverse:
         lzone, szone = szone, lzone
-    try:
-        return (date.replace(tzinfo=szone).astimezone(lzone)
-            .replace(tzinfo=None))
-    except (ValueError, OSError):
-        # https://github.com/dateutil/dateutil/issues/434
-        return date.replace(tzinfo=None)
+    return date.replace(tzinfo=szone).astimezone(lzone).replace(tzinfo=None)
 
 
 def untimezoned_date(date):