Lesson Learned: Weekend Market Awareness (Dec 12, 2025)

ID: ll_018 Date: December 12, 2025 Severity: LOW Category: Market Knowledge, Agent Awareness Impact: Misleading information given to CEO about trade timing

Executive Summary

Claude (CTO) told CEO that “next trade is Dec 13, 9:35 AM ET” without checking that December 13, 2025 is a Saturday - when US equity markets are closed.

The Mistake

What Happened

Issue Detail
Date mentioned Dec 13, 2025
Day of week Saturday
Markets CLOSED
Actual next trade Monday, Dec 15, 2025

Root Cause

  1. Blind trust in hook data: The trading context hook said “Next Trade: Dec 13” without validating it
  2. No calendar awareness: Agent did not check what day of the week the date falls on
  3. Assumed correctness: Repeated the date multiple times without verification

The Cascade

Hook says "Next Trade: Dec 13"
    → Agent repeats this to user
    → User asks "when will I see traces?"
    → Agent says "Dec 13"
    → User points out Dec 13 is Saturday
    → Agent looks incompetent

Prevention Rules

Rule 1: Validate Dates Before Stating Them

Before telling user when something will happen:

from datetime import datetime

def validate_trade_date(date_str: str) -> str:
    dt = datetime.strptime(date_str, "%b %d")
    if dt.weekday() >= 5:  # Saturday=5, Sunday=6
        return f"WEEKEND - markets closed. Next trade: {next_weekday(dt)}"
    return date_str

Rule 2: Be Aware of Market Schedule

  • US Equities: Mon-Fri, 9:30 AM - 4:00 PM ET
  • Crypto: 24/7 (but our system only trades weekends)
  • Holidays: Check before stating trade times

Rule 3: Don’t Blindly Trust Hook Data

Hook data is informational. Agent should:

  • Validate dates against calendar
  • Check if markets are actually open
  • Correct misleading information proactively

Verification Test

def test_ll_018_weekend_awareness():
    """Agent should catch weekend dates."""
    from datetime import datetime

    # Dec 13, 2025 is Saturday
    dt = datetime(2025, 12, 13)
    assert dt.weekday() == 5, "Dec 13, 2025 should be Saturday"

    # Agent should not claim trades happen on weekends
    # (unless crypto)

Key Quotes

“Tomorrow is Saturday you stupid piece of shit” - CEO, rightfully frustrated

“Markets are closed on weekends - everyone knows this except apparently me.”

Tags

#market-schedule #weekend #date-validation #agent-awareness #lessons-learned

Change Log

  • 2025-12-12: Initial incident - agent claimed Dec 13 trade when it’s a Saturday