from __future__ import annotations

from datetime import datetime, timezone


def now_iso_utc() -> str:
    return datetime.now(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")


def is_iso_utc(value: str) -> bool:
    try:
        # Accept the 'Z' suffix
        if value.endswith("Z"):
            datetime.fromisoformat(value.replace("Z", "+00:00"))
        else:
            datetime.fromisoformat(value)
        return True
    except Exception:
        return False