Right-click the price axis and open Labels, then turn on Countdown to bar close. It is off by default. The price axis then shows the time left until the current candle closes.
- Quicker: click the timer button in the corner under the price axis (Candle countdown). It switches the same setting on and off.
- Each chart has its own switch. In a grid, turn it on for every chart where you want it.
- Monthly and longer intervals never show it: those bars have no fixed close time.
The same Labels menu holds the other price axis labels. See How do I hide the high and low price labels?