fix(heartbeat): inject shared current time context into phase 1

nanobot/agent/context.py

@@ -3,11 +3,11 @@
 import base64
 import mimetypes
 import platform
-import time
-from datetime import datetime
 from pathlib import Path
 from typing import Any
 
+from nanobot.utils.helpers import current_time_str
+
 from nanobot.agent.memory import MemoryStore
 from nanobot.agent.skills import SkillsLoader
 from nanobot.utils.helpers import build_assistant_message, detect_image_mime
@@ -99,9 +99,7 @@ Reply directly with text for conversations. Only use the 'message' tool to send
     @staticmethod
     def _build_runtime_context(channel: str | None, chat_id: str | None) -> str:
         """Build untrusted runtime metadata block for injection before the user message."""
-        now = datetime.now().strftime("%Y-%m-%d %H:%M (%A)")
+        lines = [f"Current Time: {current_time_str()}"]
-        tz = time.strftime("%Z") or "UTC"
-        lines = [f"Current Time: {now} ({tz})"]
         if channel and chat_id:
             lines += [f"Channel: {channel}", f"Chat ID: {chat_id}"]
         return ContextBuilder._RUNTIME_CONTEXT_TAG + "\n" + "\n".join(lines)

nanobot/heartbeat/service.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import asyncio
-from datetime import datetime, timezone
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Callable, Coroutine
 
@@ -88,19 +87,13 @@ class HeartbeatService:
 
         Returns (action, tasks) where action is 'skip' or 'run'.
         """
-        now_str = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
+        from nanobot.utils.helpers import current_time_str
 
         response = await self.provider.chat_with_retry(
             messages=[
-                {"role": "system", "content": (
+                {"role": "system", "content": "You are a heartbeat agent. Call the heartbeat tool to report your decision."},
-                    "You are a heartbeat agent. Call the heartbeat tool to report your decision. "
-                    "The current date/time is provided so you can evaluate time-based conditions. "
-                    "Choose 'run' if there are active tasks to execute. "
-                    "Choose 'skip' if the file has no actionable tasks, if blocking conditions "
-                    "are not yet met, or if tasks are scheduled for a future time that has not arrived yet."
-                )},
                 {"role": "user", "content": (
-                    f"Current date/time: {now_str}\n\n"
+                    f"Current Time: {current_time_str()}\n\n"
                     "Review the following HEARTBEAT.md and decide whether there are active tasks.\n\n"
                     f"{content}"
                 )},

nanobot/utils/helpers.py

@@ -2,6 +2,7 @@
 
 import json
 import re
+import time
 from datetime import datetime
 from pathlib import Path
 from typing import Any
@@ -33,6 +34,13 @@ def timestamp() -> str:
     return datetime.now().isoformat()
 
 
+def current_time_str() -> str:
+    """Human-readable current time with weekday and timezone, e.g. '2026-03-15 22:30 (Saturday) (CST)'."""
+    now = datetime.now().strftime("%Y-%m-%d %H:%M (%A)")
+    tz = time.strftime("%Z") or "UTC"
+    return f"{now} ({tz})"
+
+
 _UNSAFE_CHARS = re.compile(r'[<>:"/\\|?*]')
 
 def safe_filename(name: str) -> str:

tests/test_heartbeat_service.py

@@ -253,8 +253,8 @@ async def test_decide_retries_transient_error_then_succeeds(tmp_path, monkeypatc
 
 
 @pytest.mark.asyncio
-async def test_decide_prompt_includes_current_datetime(tmp_path) -> None:
+async def test_decide_prompt_includes_current_time(tmp_path) -> None:
-    """Phase 1 prompt must contain the current date/time so the LLM can judge task urgency."""
+    """Phase 1 user prompt must contain current time so the LLM can judge task urgency."""
 
     captured_messages: list[dict] = []
 
@@ -283,14 +283,7 @@ async def test_decide_prompt_includes_current_datetime(tmp_path) -> None:
 
     await service._decide("- [ ] check servers at 10:00 UTC")
 
-    # System prompt should mention date/time awareness
-    system_msg = captured_messages[0]
-    assert system_msg["role"] == "system"
-    assert "date/time" in system_msg["content"].lower()
-
-    # User prompt should contain a UTC timestamp
     user_msg = captured_messages[1]
     assert user_msg["role"] == "user"
-    assert "Current date/time:" in user_msg["content"]
+    assert "Current Time:" in user_msg["content"]
-    assert "UTC" in user_msg["content"]