Calibration Record Agent

import pandas as pd
from datetime import datetime

def calibration_check():
    instruments = pd.read_sql("SELECT * FROM instruments")
    now = datetime.now()
    for _, inst in instruments.iterrows():
        due = pd.read_sql("SELECT due_date FROM calibration_records WHERE instrument_id = ?", inst['id'])
        if not due.empty:
            days_left = (due['due_date'] - now).days
            inst['status'] = 'Overdue' if days_left < 0 else 'Due Soon' if days_left < 30 else 'Compliant'
    return instruments