It’s a public holiday in the UK. Unless your viva is 9am tomorrow you’re probably safe to relax for a day.
Rest. Take today for you.
Don’t read your thesis, scribble in margins, chat with your supervisor or look at one more paper.
Don’t make a big list of annotations to add to your thesis or commit your ten most valuable references to memory.
Don’t make a plan for the weeks leading up to your viva and what you might do over that period.
Rest is as important as all the reading, writing and rehearsing for the viva. You might need to do some or all of the things above in preparation but you don’t need to do it today.