fix(reme): use timezone-aware datetime in memory summarization (#165)

Use user-specified timezone instead of system local time when generating
daily note filenames and timestamps in memory summarization and CLI.

Changes:
- Summarizer: accept 'timezone' param in __init__; use
  datetime.now(zoneinfo.ZoneInfo(tz)) instead of naive datetime.now()
- ReMeLight.summary_memory(): accept 'timezone' param and pass to Summarizer
- CliAgent: accept 'timezone' param in __init__; pass to Summarizer
  and use for current_time timestamp in system prompts
- Fallback to system local time if timezone is None (preserves original behavior)

Fixes timezone mismatch when system timezone differs from user's actual
location (e.g., server in UTC+8 but user in America/Chicago).

reme/memory/file_based/components/cli.py

@@ -3,6 +3,7 @@
 import asyncio
 from datetime import datetime
 from pathlib import Path
+import zoneinfo
 
 from agentscope.agent import ReActAgent
 from agentscope.message import Msg, TextBlock
@@ -46,6 +47,7 @@ class CliAgent(BaseOp):
         reserve_tokens: int = 36000,
         keep_recent_tokens: int = 20000,
         language: str = "zh",
+        timezone: str | None = None,
         **kwargs,
     ):
         super().__init__(**kwargs)
@@ -57,6 +59,7 @@ class CliAgent(BaseOp):
         self.reserve_tokens: int = reserve_tokens
         self.keep_recent_tokens: int = keep_recent_tokens
         self.language: str = language
+        self.timezone: str | None = timezone
 
         # Initialize message history
         self.messages: list[Msg] = []
@@ -93,6 +96,7 @@ class CliAgent(BaseOp):
             as_llm_formatter=self.as_llm_formatter,
             language=self.language if self.language == "zh" else "",
             console_enabled=False,  # We disable the terminal printing to avoid messy outputs
+            timezone=self.timezone,
         )
 
         # Create summary task
@@ -168,6 +172,7 @@ class CliAgent(BaseOp):
             as_llm_formatter=self.as_llm_formatter,
             language=self.language if self.language == "zh" else "",
             console_enabled=False,  # We disable the terminal printing to avoid messy outputs
+            timezone=self.timezone,
         )
 
         summary_content = await compactor.call(
@@ -195,7 +200,8 @@ class CliAgent(BaseOp):
 
     async def _build_messages(self, query: str) -> list[Msg]:
         """Build system prompt message."""
-        current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S %A")
+        tz = zoneinfo.ZoneInfo(self.timezone) if self.timezone else None
+        current_time = datetime.now(tz).strftime("%Y-%m-%d %H:%M:%S %A")
 
         # Create system prompt
         system_prompt = self.prompt_format(

reme/memory/file_based/components/summarizer.py

@@ -1,6 +1,7 @@
 """Summarizer module for memory summarization operations."""
 
 import datetime
+import zoneinfo
 
 from agentscope.agent import ReActAgent
 from agentscope.message import Msg
@@ -23,6 +24,7 @@ class Summarizer(BaseOp):
         memory_compact_threshold: int,
         toolkit: Toolkit | None = None,
         console_enabled: bool = False,
+        timezone: str | None = None,
         **kwargs,
     ):
         super().__init__(**kwargs)
@@ -31,6 +33,7 @@ class Summarizer(BaseOp):
         self.memory_compact_threshold: int = memory_compact_threshold
         self.toolkit: Toolkit | None = toolkit
         self.console_enabled: bool = console_enabled
+        self.timezone: str | None = timezone
 
     async def execute(self):
         messages: list[Msg] = self.context.get("messages", [])
@@ -62,7 +65,13 @@ class Summarizer(BaseOp):
 
         user_message: str = f"<conversation>\n{history_formatted_str}\n</conversation>\n" + self.prompt_format(
             "user_message",
-            date=datetime.datetime.now().strftime("%Y-%m-%d"),
+            date=(
+                datetime.datetime.now(
+                    zoneinfo.ZoneInfo(self.timezone),
+                )
+                if self.timezone
+                else datetime.datetime.now()
+            ).strftime("%Y-%m-%d"),
             working_dir=self.working_dir,
             memory_dir=self.memory_dir,
         )

reme/reme_light.py

@@ -406,6 +406,7 @@ class ReMeLight(Application):
         language: str = "zh",
         max_input_length: float = 128 * 1024,
         compact_ratio: float = 0.7,
+        timezone: str | None = None,
     ) -> str:
         """
         Generate a comprehensive summary of the given messages.
@@ -430,6 +431,8 @@ class ReMeLight(Application):
                 Defaults to 128K tokens.
             compact_ratio (float): Ratio used to calculate compaction threshold.
                 Defaults to 0.7.
+            timezone (str | None): Timezone string for date formatting
+                (e.g., "America/Chicago"). Defaults to system local time if None.
 
         Returns:
             str: The generated summary text, or an empty string if an error occurred.
@@ -455,6 +458,7 @@ class ReMeLight(Application):
                 as_llm_formatter=as_llm_formatter,
                 as_token_counter=as_token_counter,
                 language=language if language == "zh" else "",
+                timezone=timezone,
             )
 
             return await summarizer.call(messages=messages, service_context=self.service_context)