fix: parse naive date/time strings in to_time's target timezone (#1359)

* fix: interpret naive time date strings in target timezone

* test: cover naive and offset time date strings

src/akkudoktoreos/utils/datetimeutil.py

@@ -672,12 +672,15 @@ def to_time(
             - pendulum.Time or pendulum.DateTime
             - datetime.time or datetime.datetime
             - strings like "14:30", "2:30 PM", "1430", "14:30:00.123", "2PM", "14h30"
+            - date/time strings (e.g. "2026-01-15T23:45")
             - int (e.g. 14 → 14:00)
             - float (e.g. 14.5 → 14:30)
             - tuple like (14,), (14, 30), (14, 30, 15)
 
         in_timezone: Optional timezone name or object (e.g., "Europe/Berlin").
-            Defaults to the local timezone.
+            Defaults to the local timezone. Date/time strings without an offset use this
+            timezone as their wall time; strings with `Z` or an offset represent an instant
+            that is converted to this timezone.
 
         to_naive: If True, return a timezone-naive Time object.
 
@@ -812,16 +815,18 @@ def to_time(
 
             # Fallback to pendulum's parser
             try:
-                dt = cast(pendulum.DateTime, pendulum.parse(value, strict=False)).in_tz(timezone)
+                dt = cast(
+                    pendulum.DateTime, pendulum.parse(value, tz=timezone, strict=False)
+                ).in_tz(timezone)
                 return finalize(dt.time())
             except Exception as e:
                 logger.trace(f"Pendulum parser failed for '{value}': {e}")
 
             # Try parsing with ISO time prefix
             try:
-                dt = cast(pendulum.DateTime, pendulum.parse(f"T{value}", strict=False)).in_tz(
-                    timezone
-                )
+                dt = cast(
+                    pendulum.DateTime, pendulum.parse(f"T{value}", tz=timezone, strict=False)
+                ).in_tz(timezone)
                 return finalize(dt.time())
             except Exception as e:
                 logger.trace(f"ISO time parser failed for 'T{value}': {e}")
@@ -829,7 +834,8 @@ def to_time(
             # Try parsing as part of a full datetime
             try:
                 dt = cast(
-                    pendulum.DateTime, pendulum.parse(f"2000-01-01 {value}", strict=False)
+                    pendulum.DateTime,
+                    pendulum.parse(f"2000-01-01 {value}", tz=timezone, strict=False),
                 ).in_tz(timezone)
                 return finalize(dt.time())
             except Exception as e:

tests/test_datetimeutil.py

@@ -675,6 +675,36 @@ class TestToTime:
         assert result.minute == 30
         assert result.second == 45
 
+    @pytest.mark.parametrize("host_timezone", ["UTC", "America/New_York"])
+    @pytest.mark.parametrize(
+        "value, expected_time, expected_microsecond",
+        [
+            ("2026-01-15T23:45", "23:45:00", 0),
+            ("2026-07-15 23:45", "23:45:00", 0),
+            ("2026-01-15 23:45:30", "23:45:30", 0),
+            ("2026-07-15T23:45:30.123456", "23:45:30", 123456),
+            ("2026-07-15T23:45Z", "01:45:00", 0),
+            ("2026-01-15 23:45+00:00", "00:45:00", 0),
+            ("2026-07-15T23:45:30.123456+03:00", "22:45:30", 123456),
+        ],
+    )
+    def test_to_time_datetime_strings_use_target_timezone(
+        self, set_other_timezone, host_timezone, value, expected_time, expected_microsecond
+    ):
+        set_other_timezone(host_timezone)
+        result = to_time(value, in_timezone="Europe/Berlin")
+        assert isinstance(result, Time)
+        assert result.format("HH:mm:ss") == expected_time
+        assert result.microsecond == expected_microsecond
+
+    @pytest.mark.parametrize("local_timezone", ["Europe/Berlin", "America/New_York"])
+    def test_to_time_naive_datetime_string_defaults_to_local_timezone(
+        self, set_other_timezone, local_timezone
+    ):
+        set_other_timezone(local_timezone)
+        assert to_time("2026-01-15T23:45", as_string="HH:mm:ss") == "23:45:00"
+        assert to_time("23:45", as_string="HH:mm:ss") == "23:45:00"
+
     @patch('akkudoktoreos.utils.datetimeutil.logger.trace')
     def test_to_time_logging_on_parse_failures(self, mock_trace):
         """Test that parsing failures are logged appropriately."""