The age of the universe at 13.7 billion years is based on the assumption that space is expanding and time is not. But if time is expanding then this number is wrong. Or rather it is only correct from a single reference point. A reference point that is likely very back in the past.

If you were to assume that time is expanding at the same rate as space then it should be possible to find out a true age of the universe. The universe has an age that is absolute and one that is relativistic based on the expansion of time.

For example if event B happened 1 second after event A from the reference point of right now. Then many years in the future after time has sufficently expanded, we could say that event B actually happened 2 seconds after event A and this would atually be correct since time is expanding.

What makes this even more intresting is the idea that time is expanding in both directions. This would mean that future events are getting further away from us. And if time truly does have more than one dimension, then i am not sure if the current understanding of physics is sufficient to predict the future at all.