Today is always today. Yesterday is always yesterday. And future is always future. So how can you live in the past if it's yesterday and you live in the present that is today and future does never happen because things can only happen in the present?
I would have to disagree. If you are standing on the prime meridian at midnight, you're probebly underwater. But assuming you're still alive, and talking to somebody on the other side of the prime meridian, then when you say "today", you'll be talking about a differrent "today" from the one they would understand.