Basically, spacetime, the arrow of time, etc...... it's still a dance to explain time, yet perfectly acceptable to continue to search for answers..
I would say that there are several understandings of time and it is important to know which one you are dealing with.
In a room full of physicists, you need to pretty much go with what physics says (ie. the spacetime as described by the math of relativity). And that is a well-established theory, too. For instance, we use it to correct the clocks of GPS satellites relative to their ground stations. It has been argued that there is, in fact, no such thing as time but that's going beyond relativity and is still controversial.
Historians see time in terms of the changes that happen in society. This event happened before that event. There is an agreed upon time scale on which we pin these events so we can establish what happened first or what led to what.
Which is similar to how past time is experienced by us everyday but the events are smaller in scope. Graduation, first kiss, marriage, and so on instead of which king ruled when or which battle led to which other battle. The agreed upon scale is in years or even months instead of decades and centuries.
In everyday life, we experience time more subjectively and we can define it that way, but it's not something you can measure or describe mathematically. Living in the present means living in your own present as you experience it, but no one else can experience it that way. Sometimes an hour feels like forever, sometimes days fly by, but that's our experience, not reality. The clock still ticks at the same pace.
And, you're right, that puts on a similar footing with faith.
Faith is something you experience in your own life and space but you cannot measure it in reproducible way or describe it mathematically or expect someone else to experience it the same way. Which is agnosticism, at least in a philosophical sense. You cannot prove your faith to me in a scientific way any more than you can prove that an hour at work goes slower than an hour having fun with your partner.
Which one do we live in? The everyday life one, of course. Though, again, dwelling on the past or fretting about the future may distort that experience in one direction or the other.
