from datetime import date, datetime, timezone, timedelta

CST = timezone(timedelta(hours=8))  # China Standard Time


def today_cst() -> date:
    """Get today's date in Asia/Shanghai timezone."""
    return datetime.now(timezone.utc).astimezone(CST).date()


def parse_date(s: str) -> date:
    """Parse a date string that may be YYYY-MM-DD or a full ISO datetime."""
    return date.fromisoformat(s[:10])