There’s a time frame for completing your PhD, for preparing for the viva and for engaging with it on the day. Each is measured differently of course! Years for a PhD, weeks for preparation, hours for the viva. You might feel busy or pressured, but with all of these stages of the journey you can take your time.
In the viva particularly you can take your time. It’s not a quick fire quiz. It’s not scoring points. The questions are not random and the questioners are not unknown. The process is clear, even if every question is not known ahead of time. Pause, think, respond. Engage with your examiners’ questions.
Take your time. Nobody really wants a four hour viva – I know from personal experience! – but however long your viva is will be right for you. It will be what was needed, driven by the number of questions your examiners have and how you approach them.
Take your time. You do not need to rush to finish, now that everything is nearly done.