Edit domain - fix converting to time variable when timezone set

Orange/widgets/data/oweditdomain.py

@@ -2828,7 +2828,15 @@ def transform(self, c):
 
 def datetime_to_epoch(dti: pd.DatetimeIndex, only_time) -> np.ndarray:
     """Convert datetime to epoch"""
-    delta = dti - (dti.normalize() if only_time else pd.Timestamp("1970-01-01"))
+    # when dti has timezone info also the subtracted timestamp must have it
+    # otherwise subtracting fails
+    initial_ts = pd.Timestamp("1970-01-01", tz=None if dti.tz is None else "UTC")
+    # pandas in versions before 1.4 don't support subtracting different timezones
+    # remove next two lines when read-the-docs start supporting config files
+    # for subprojects, or they change default python version to 3.8
+    if dti.tz is not None:
+        dti = dti.tz_convert("UTC")
+    delta = dti - (dti.normalize() if only_time else initial_ts)
     return (delta / pd.Timedelta("1s")).values
 
 

Orange/widgets/data/tests/test_oweditdomain.py

@@ -921,13 +921,18 @@ def test_as_time(self):
         times = (
             ["07.02.2022", "18.04.2021"],  # date only
             ["07.02.2022 01:02:03", "18.04.2021 01:02:03"],  # datetime
+            # datetime with timezone
+            ["2021-02-08 01:02:03+01:00", "2021-02-07 01:02:03+01:00"],
             ["010203", "010203"],  # time
             ["02-07", "04-18"],
         )
-        formats = ["25.11.2021", "25.11.2021 00:00:00", "000000", "11-25"]
+        formats = [
+            "25.11.2021", "25.11.2021 00:00:00", "2021-11-25 00:00:00", "000000", "11-25"
+        ]
         expected = [
             [d("2022-02-07"), d("2021-04-18")],
             [d("2022-02-07 01:02:03"), d("2021-04-18 01:02:03")],
+            [d("2021-02-08 01:02:03+0100"), d("2021-02-07 01:02:03+0100")],
             [d("01:02:03"), d("01:02:03")],
             [d("1900-02-07"), d("1900-04-18")],
         ]
@@ -952,6 +957,16 @@ def test_as_time(self):
             np.array(list(chain(expected, expected)), dtype=float).transpose()
         )
 
+    def test_raise_pandas_version(self):
+        """
+        When this test start to fail:
+        - remove this test
+        - remove if clause in datetime_to_epoch function and supporting comments
+        - set pandas dependency version to pandas>=1.4
+        """
+        from datetime import datetime
+        self.assertLess(datetime.today(), datetime(2023, 1, 1))
+
     def test_reinterpret_string(self):
         table = self.data_str
         domain = table.domain