I know there are other hypotheses on time, but for this question lets go with this definition of time:
The indefinite, constant, continued progress of existence.
Now we have the three parts of time: The past, present and the future.
Lets define the past as:
Passed by in time and no longer existing
And the future as:
Moments yet to happen in time
And lets also say that the past is fixed and the future isn't.
Now the present is:
Existing or occurring now or at this point in time.
My problem here is the word 'now'.
If time is ever continuing and constant, then 'now' surely doesn't exist.
The particular point will be infinitely small and if we are constantly moving into the future, then the present will be part of the past - as what we see 'now' takes time to reach our eyes and by the time it's processed will already be in the past.
So is there just a past and a future? Can it be that there is no such time as the present?
As I see it there are two possibilities:
There is no such thing as the present, just the past and future and we are inbetween
There is an infinitely small point in time which is the present (represented by the line), which is constantly moving forward into the future
Forget all loopholes, wormholes and other time-related problems for this.