I agree that Time exists only as a concept because we humans created it. However, there has to be something out there that forbids events from happening all at once.
Something that forbids events from happening all at once... I think Kasroa is right in saying space-time is that something.
So somehow is no events took place, would time still exist to contain these non-events? or would a non-event, in effect, be an event?
If no events took place there would be no way to measure time, which is about all we can do to get our grimy fingers around it. So I suppose in that case there would be no time and also no events, no objects, no anything.
This "time" thing seems to me to be just like another space dimension, except that we can only experience one point of its length: right now. For some reason we are just slowly rolling through this 4th dimension at a constant rate. We lack completely the ability to push ourselves around in this "time" dimension. we can only look on as we, in our three visible dimensions, pass through the fourth just like the 3-D sphere passes through this 2-D plane:

We know time because it exists. Or it exists because we know time. All things being relative, there is no difference between the two statements. Reality is beyond words. One must not confuse the world of things -- as we think about, talk about, and name -- with the world as it actually is. The sound of rain needs no translation. Time exists without us; it is we that are impermanent.