Bump minimum Python version to 3.11

Python 3.10 enters security-only phase in April 2026 and reaches EOL
in October 2026. Raise minimum to 3.11 in pyproject.toml, update the
ruff target-version, and adopt datetime.UTC (py3.11+) in place of
timezone.utc throughout.

Author: fprochazka

.python-version

@@ -1 +1 @@
-3.10
+3.11

pyproject.toml

@@ -3,7 +3,7 @@ name = "slackcli"
 version = "0.1.0"
 description = "A command-line interface for Slack"
 readme = "README.md"
-requires-python = ">=3.10"
+requires-python = ">=3.11"
 dependencies = [
     "certifi>=2024.0.0",
     "rich>=14.3.2",
@@ -29,7 +29,7 @@ packages = ["src/slackcli"]
 
 [tool.ruff]
 line-length = 120
-target-version = "py310"
+target-version = "py311"
 
 [tool.ruff.lint]
 select = ["E", "F", "I", "UP", "B", "C4", "SIM"]

src/slackcli/commands/pins.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from typing import TYPE_CHECKING, Annotated, Any
 
 import typer
@@ -56,7 +56,7 @@ def _format_pinned_item(
     if msg_ts:
         try:
             ts_float = float(msg_ts)
-            dt = datetime.fromtimestamp(ts_float, tz=timezone.utc)
+            dt = datetime.fromtimestamp(ts_float, tz=UTC)
             datetime_str = dt.strftime("%Y-%m-%d %H:%M:%S")
         except (ValueError, OSError):
             datetime_str = msg_ts
@@ -170,7 +170,7 @@ def list_pins(
                     pinned_at = ""
                     if pin["pinned_at"]:
                         try:
-                            dt = datetime.fromtimestamp(pin["pinned_at"], tz=timezone.utc)
+                            dt = datetime.fromtimestamp(pin["pinned_at"], tz=UTC)
                             pinned_at = f" on {dt.strftime('%Y-%m-%d')}"
                         except (ValueError, OSError):
                             pass

src/slackcli/commands/search.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from typing import TYPE_CHECKING, Annotated, Any
 
 import typer
@@ -169,7 +169,7 @@ def output_search_messages_text(
 
         # Parse timestamp
         try:
-            dt = datetime.fromtimestamp(float(ts), tz=timezone.utc)
+            dt = datetime.fromtimestamp(float(ts), tz=UTC)
             date_str = dt.strftime("%Y-%m-%d %H:%M")
         except (ValueError, OSError):
             date_str = ts
@@ -222,7 +222,7 @@ def output_search_files_text(
 
         # Format date
         try:
-            dt = datetime.fromtimestamp(created, tz=timezone.utc)
+            dt = datetime.fromtimestamp(created, tz=UTC)
             date_str = dt.strftime("%Y-%m-%d %H:%M")
         except (ValueError, OSError):
             date_str = str(created)

src/slackcli/models.py

@@ -10,7 +10,7 @@
 import re
 from collections.abc import Callable
 from dataclasses import dataclass, field
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from typing import Any
 
 # Type alias for message text extraction and mention resolution functions
@@ -149,7 +149,7 @@ class Message:
     def datetime(self) -> datetime | None:
         """Get the message timestamp as a datetime object."""
         try:
-            return datetime.fromtimestamp(float(self.ts), tz=timezone.utc)
+            return datetime.fromtimestamp(float(self.ts), tz=UTC)
         except (ValueError, OSError):
             return None
 

src/slackcli/time_utils.py

@@ -7,7 +7,7 @@
 from __future__ import annotations
 
 import re
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 
 
 def parse_relative_time(spec: str, base: datetime | None = None) -> timedelta | None:
@@ -92,7 +92,7 @@ def parse_time_spec(spec: str) -> datetime:
         ValueError: If spec cannot be parsed.
     """
     spec_lower = spec.strip().lower()
-    now = datetime.now(tz=timezone.utc)
+    now = datetime.now(tz=UTC)
 
     # Keywords
     if spec_lower == "today":
@@ -112,7 +112,7 @@ def parse_time_spec(spec: str) -> datetime:
     if dt is not None:
         # If no timezone, assume UTC
         if dt.tzinfo is None:
-            dt = dt.replace(tzinfo=timezone.utc)
+            dt = dt.replace(tzinfo=UTC)
         return dt
 
     raise ValueError(f"Cannot parse time specification: {spec}")
@@ -136,7 +136,7 @@ def parse_date_spec(spec: str) -> str:
         ValueError: If spec cannot be parsed.
     """
     spec_lower = spec.strip().lower()
-    now = datetime.now(tz=timezone.utc)
+    now = datetime.now(tz=UTC)
 
     # Keywords
     if spec_lower == "today":

tests/test_time_utils.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 
 import pytest
 
@@ -72,39 +72,39 @@ class TestParseTimeSpec:
     def test_today_keyword(self) -> None:
         """Test 'today' keyword returns start of today in UTC."""
         result = parse_time_spec("today")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         expected = now.replace(hour=0, minute=0, second=0, microsecond=0)
         assert result == expected
 
     def test_yesterday_keyword(self) -> None:
         """Test 'yesterday' keyword returns start of yesterday in UTC."""
         result = parse_time_spec("yesterday")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         expected = (now - timedelta(days=1)).replace(hour=0, minute=0, second=0, microsecond=0)
         assert result == expected
 
     def test_now_keyword(self) -> None:
         """Test 'now' keyword returns current time in UTC."""
-        before = datetime.now(tz=timezone.utc)
+        before = datetime.now(tz=UTC)
         result = parse_time_spec("now")
-        after = datetime.now(tz=timezone.utc)
+        after = datetime.now(tz=UTC)
         assert before <= result <= after
 
     def test_relative_times(self) -> None:
         """Test relative time specifications."""
-        before = datetime.now(tz=timezone.utc)
+        before = datetime.now(tz=UTC)
         result = parse_time_spec("7d")
-        after = datetime.now(tz=timezone.utc)
+        after = datetime.now(tz=UTC)
 
         expected_min = before - timedelta(days=7)
         expected_max = after - timedelta(days=7)
         assert expected_min <= result <= expected_max
 
     def test_relative_hours(self) -> None:
         """Test relative hour specifications."""
-        before = datetime.now(tz=timezone.utc)
+        before = datetime.now(tz=UTC)
         result = parse_time_spec("2h")
-        after = datetime.now(tz=timezone.utc)
+        after = datetime.now(tz=UTC)
 
         expected_min = before - timedelta(hours=2)
         expected_max = after - timedelta(hours=2)
@@ -113,19 +113,19 @@ def test_relative_hours(self) -> None:
     def test_iso_date(self) -> None:
         """Test ISO date parsing."""
         result = parse_time_spec("2024-01-15")
-        expected = datetime(2024, 1, 15, 0, 0, 0, tzinfo=timezone.utc)
+        expected = datetime(2024, 1, 15, 0, 0, 0, tzinfo=UTC)
         assert result == expected
 
     def test_iso_datetime_with_t(self) -> None:
         """Test ISO datetime parsing with T separator."""
         result = parse_time_spec("2024-01-15T10:30:00")
-        expected = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+        expected = datetime(2024, 1, 15, 10, 30, 0, tzinfo=UTC)
         assert result == expected
 
     def test_iso_datetime_with_space(self) -> None:
         """Test ISO datetime parsing with space separator."""
         result = parse_time_spec("2024-01-15 10:30:00")
-        expected = datetime(2024, 1, 15, 10, 30, 0, tzinfo=timezone.utc)
+        expected = datetime(2024, 1, 15, 10, 30, 0, tzinfo=UTC)
         assert result == expected
 
     def test_case_insensitive_keywords(self) -> None:
@@ -154,27 +154,27 @@ class TestParseDateSpec:
     def test_today_keyword(self) -> None:
         """Test 'today' keyword returns today's date."""
         result = parse_date_spec("today")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         assert result == now.strftime("%Y-%m-%d")
 
     def test_yesterday_keyword(self) -> None:
         """Test 'yesterday' keyword returns yesterday's date."""
         result = parse_date_spec("yesterday")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         expected = (now - timedelta(days=1)).strftime("%Y-%m-%d")
         assert result == expected
 
     def test_relative_days(self) -> None:
         """Test relative day specifications."""
         result = parse_date_spec("7d")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         expected = (now - timedelta(days=7)).strftime("%Y-%m-%d")
         assert result == expected
 
     def test_relative_30_days(self) -> None:
         """Test 30 days ago."""
         result = parse_date_spec("30d")
-        now = datetime.now(tz=timezone.utc)
+        now = datetime.now(tz=UTC)
         expected = (now - timedelta(days=30)).strftime("%Y-%m-%d")
         assert result == expected