Time As A Dimension

Time is the indefinite continued progress of existence and events that occur in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred to as a fourth dimension, along with three spatial dimensions.  SOURCE:  WIKIPEDIA

Time is just as good a dimension as space is, as no matter how you boost yourself through space, you must always move forward through time.  If time weren't a dimension with the exact properties it possesses, special relativity would be invalid, and we could not construct spacetime to describe our Universe.

So, do you think time is a dimension?

In physics and mathematics, the dimension of a mathematical space is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it – for example, the point at 5 on a number line.

But is time a number that denotes movement or does time have its own dimensional qualities like:  depth, height, and width?

We refer to space-time but only because we see space as moving forward not backward and that movement forward is measured by the passing of time.  

But, is there time before it happens?

Tomorrow has not happened yet and because there was a yesterday and a today, we can assume that there will be a tomorrow but what about time...  has tomorrow's time already taken place?  And, if it has how can we guarantee that it is moving forward and not backward to accommodate our moving forward?

We cannot...   all we can do is imagine and speculate based upon historical data.