You can tell at a glance whether the market is open, right next to the symbol.
Green dot: the CME market is open and trading.
Red dot with a Closed badge: the market is shut.
This follows CME trading hours. Futures do not trade 24/7, they have a daily close and weekend closure, so knowing the state matters before you place an order.
The candle countdown
The countdown to the next candle pauses while the market is closed, and updates live with no refresh needed. New candles open right at the interval boundary instead of lagging behind, and no candle is drawn while the market is shut.