What time do you think you have?

Time. Consciousness. Existence. Nothing. Perfection. Knowledge. Truth.

Seven of the oddest concepts that I have ever run into.

Time wasn't ever odd to me until I ran into a book titled: "The Calendar" which seems to suggest (I haven't actually read it) that time is entirely a human invention.

What is time?
The only purpose and defining feature of time seems to be that it is a measurement between a past and current event.

So five ideas that have been driving me crazy:

1. Can one reach a point at which time can no longer be divided into smaller units? If so then it would seem as though time does not exist at each one of those moments because there would be nothing to compare it to.

2. If it were entirely possible for something to not change for say, one second, would a measurement of time necessarily skip that one second?

3. Seeing as one is always living in the present moment, never in the past, and never in the future, can we conclude that there are truly such things as the past and the future? Are the past and the future the present?

4. If, as many religions suggest, time will not exist after death doesn't this mean that there can be only the options of a sort of Buddhist-nothingness after death, or an existence for persons which is stuck in one mode so that if one had a body that body could never move, eat, talk, etc. because doing so would allow time back into the game board as a measurement between when the person did and did not act?

5. If time is cylical would the circle of time taken as a whole, meaning the greatest time unit that could be reached, be the measurement at which time does not exist because one time around the circle would be the same as the next time around the circle and so on and would, thus, indicate not a measurement of change, but instead a pattern?