TimeVariable: handle different timezones

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/tests/test_variable.py

@@ -15,7 +15,6 @@
 import numpy as np
 import scipy.sparse as sp
 
-import Orange
 from Orange.data import Variable, ContinuousVariable, DiscreteVariable, \
     StringVariable, TimeVariable, Unknown, Value, Table
 from Orange.data.io import CSVReader
@@ -695,6 +694,15 @@ def varcls_modified(self, name):
         var.have_time = 1
         return var
 
+    def test_remove_deprecated_utc_offset(self):
+        """ When this test start to fail:
+        - remove all marked locations in TimeVariable class
+        - uncomment new implementation for setting timezones in parse method
+        - remove this test
+        """
+        import Orange  # pylint: disable=import-outside-toplevel
+        self.assertLess(Orange.__version__, "3.32")
+
 
 PickleContinuousVariable = create_pickling_tests(
     "PickleContinuousVariable",

Orange/data/variable.py

@@ -934,29 +934,52 @@ 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 3.32
+    _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 3.32 - from here
     @property
     def utc_offset(self):
         warnings.warn(
-            "utc_offset is deprecated and will be removed in Orange 3.31",
+            "utc_offset is deprecated and will be removed in Orange 3.32",
             OrangeDeprecationWarning
         )
         return self._utc_offset
 
     @utc_offset.setter
     def utc_offset(self, val):
         warnings.warn(
-            "utc_offset is deprecated and will be removed in Orange 3.31",
+            "utc_offset is deprecated and will be removed in Orange 3.32ß",
             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, tz):
+        """
+        Set timezone value:
+        - if self._timezone is None set it to  new 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 self._timezone is None:
+            self._timezone = tz
+        elif tz != self.timezone:
+            self._timezone = "different timezones"
 
     def copy(self, compute_value=Variable._CopyComputeValue, *, name=None, **_):
         return super().copy(compute_value=compute_value, name=name,
@@ -1043,16 +1066,15 @@ def parse(self, datestr):
         else:
             raise self.InvalidDateTimeFormatError(datestr)
 
-        # Remember UTC offset. If not all parsed values share the same offset,
-        # remember none of it.
         offset = dt.utcoffset()
+        self.timezone = timezone(offset) if offset is not None else None
+        # deprecated - remove in 3.32 - from here
         if self._utc_offset is not False:
             if offset and self._utc_offset is None:
                 self._utc_offset = offset
-                self.timezone = timezone(offset)
             elif self._utc_offset != offset:
                 self._utc_offset = False
-                self.timezone = timezone.utc
+        # remove to here
 
         # Convert time to UTC timezone. In dates without timezone,
         # localtime is assumed. See also: