TimeVariable: handle different timezones

Author: PrimozGodec

Orange/data/tests/test_pandas.py

@@ -309,7 +309,6 @@ def test_table_from_frame_timezones(self):
             ]
         )
         table = table_from_frame(df)
-        self.assertIsNone(table.domain.variables[0].utc_offset)
         self.assertEqual(table.domain.variables[0].timezone, timezone.utc)
 
         df = pd.DataFrame(

Orange/data/variable.py

@@ -934,14 +934,15 @@ def __init__(self, date_string):
     # UTC offset and associated timezone. If parsed datetime values provide an
     # offset, it is used for display. If not all values have the same offset,
     # +0000 (=UTC) timezone is used and utc_offset is set to False.
-    _utc_offset = None
-    timezone = timezone.utc
+    _utc_offset = None  # deprecated - remove in 3.31
+    _timezone = None
 
     def __init__(self, *args, have_date=0, have_time=0, **kwargs):
         super().__init__(*args, **kwargs)
         self.have_date = have_date
         self.have_time = have_time
 
+    # deprecated - remove in 3.31 - from here
     @property
     def utc_offset(self):
         warnings.warn(
@@ -957,6 +958,29 @@ def utc_offset(self, val):
             OrangeDeprecationWarning
         )
         self._utc_offset = val
+    # remove to here
+
+    @property
+    def timezone(self):
+        if self._timezone is None or self._timezone == "different timezones":
+            return timezone.utc
+        else:
+            return self._timezone
+
+    @timezone.setter
+    def timezone(self, timezone):
+        """
+        Set timezone value:
+        - if self._timezone is None set it to timezone
+        - if current timezone is different that new indicate that TimeVariable
+          have two date-times with different timezones
+        - if timezones are same keep it
+        """
+        if timezone is not None:
+            if self._timezone is None:
+                self._timezone = timezone
+            elif timezone != self.timezone:
+                self._timezone = "different timezones"
 
     def copy(self, compute_value=Variable._CopyComputeValue, *, name=None, **_):
         return super().copy(compute_value=compute_value, name=name,
@@ -1043,6 +1067,7 @@ def parse(self, datestr):
         else:
             raise self.InvalidDateTimeFormatError(datestr)
 
+        # deprecated - remove in 3.31 - from here
         # Remember UTC offset. If not all parsed values share the same offset,
         # remember none of it.
         offset = dt.utcoffset()
@@ -1053,6 +1078,10 @@ def parse(self, datestr):
             elif self._utc_offset != offset:
                 self._utc_offset = False
                 self.timezone = timezone.utc
+        # remote to here
+        # offset = dt.utcoffset()  # uncomment in 3.31
+        # if offset
+        #     self.timezone = timezone(dt.utcoffset())
 
         # Convert time to UTC timezone. In dates without timezone,
         # localtime is assumed. See also: