Render tz-aware times as local times without an offset

tests/test_items.py

@@ -844,6 +844,23 @@ def test_datetimes_behave_like_datetimes_fold() -> None:
     assert k.fold == 1
 
 
+def test_time_with_tzinfo_renders_as_local_time() -> None:
+    # TOML local times have no offset/timezone; a tz-aware time must
+    # render without its offset, otherwise the output is not valid TOML
+    # and this library's own parser cannot read it back. The offset is
+    # not representable in the format, so a round-trip yields the local
+    # (naive) time.
+    tz = timezone(timedelta(hours=2))
+    i = item(time(7, 32, tzinfo=tz))
+    assert i.as_string() == "07:32:00"
+    assert parse(f"t = {i.as_string()}")["t"] == time(7, 32)
+
+    # replace() keeps the same rendering rule.
+    j = i.replace(hour=13)
+    assert j.as_string() == "13:32:00"
+    assert parse(f"t = {j.as_string()}")["t"] == time(13, 32)
+
+
 def test_strings_behave_like_strs() -> None:
     i = item("foo")
 

tomlkit/items.py

@@ -206,7 +206,7 @@ def item(value: Any, _parent: Item | None = None, _sort_keys: bool = False) -> I
             value.microsecond,
             value.tzinfo,
             Trivia(),
-            value.isoformat(),
+            _format_time(value),
             fold=value.fold,
         )
     else:
@@ -234,6 +234,18 @@ def item(value: Any, _parent: Item | None = None, _sort_keys: bool = False) -> I
     raise ConvertError(f"Unable to convert an object of {type(value)} to a TOML item")
 
 
+def _format_time(value: time) -> str:
+    # TOML local times carry no offset or timezone (the spec's examples
+    # are plain ``07:32:00``); keeping the offset in the rendered raw
+    # value would produce a literal this library's own parser rejects.
+    # Built from the fields (not ``isoformat``/``replace``) so it stays
+    # correct even when called on a ``Time`` from ``Time._new``.
+    s = f"{value.hour:02d}:{value.minute:02d}:{value.second:02d}"
+    if value.microsecond:
+        s += f".{value.microsecond:06d}".rstrip("0")
+    return s
+
+
 class StringType(Enum):
     # Single Line Basic
     SLB = '"'
@@ -1320,7 +1332,7 @@ def replace(self, *args: object, **kwargs: object) -> Time:
         return self._new(super().replace(*args, **kwargs))  # type: ignore[arg-type]
 
     def _new(self, result: time) -> Time:
-        raw = result.isoformat()
+        raw = _format_time(result)
 
         return Time(
             result.hour,