fix: patch cache bust in the system prompt via timestamp [LET-4155] (#4375)

fix: patch cache bust in the system prompt via timestamp

Author: cpacker

letta/helpers/datetime_helpers.py

@@ -20,11 +20,13 @@ def datetime_to_timestamp(dt):
 
 def get_local_time_fast(timezone):
     # Get current UTC time and convert to the specified timezone
+    # Only return the date to avoid cache busting on every request
     if not timezone:
-        return datetime.now().strftime("%Y-%m-%d %I:%M:%S %p %Z%z")
+        return datetime.now().strftime("%B %d, %Y")
     current_time_utc = datetime.now(pytz.utc)
     local_time = current_time_utc.astimezone(pytz.timezone(timezone))
-    formatted_time = local_time.strftime("%Y-%m-%d %I:%M:%S %p %Z%z")
+    # Return only the date in a human-readable format (e.g., "June 1, 2021")
+    formatted_time = local_time.strftime("%B %d, %Y")
 
     return formatted_time
 

letta/prompts/prompt_generator.py

@@ -52,7 +52,7 @@ def compile_memory_metadata_block(
         # Create a metadata block of info so the agent knows about the metadata of out-of-context memories
         metadata_lines = [
             "<memory_metadata>",
-            f"- The current time is: {get_local_time_fast(timezone)}",
+            f"- The current system date is: {get_local_time_fast(timezone)}",
             f"- Memory blocks were last modified: {timestamp_str}",
             f"- {previous_message_count} previous messages between you and the user are stored in recall memory (use tools to access them)",
         ]