Time, in terms of the greater universal cosmic reality, is unequivocally real. It it were not so, there would be no greater universal cosmic reality, nor a quantum reality which within its bazaar realm might represent the quintessential component of that reality. As Albert Einstein rationalized more than a hundred years ago, time is an integral component of reality and in combination with space, its mathematical reciprocal, represents a very tangible 4th temporal dimension of the universal reality. Unfortunately, since the common human brain is trapped in a sensually restricted 3-dimensional paradigm, envisioning the 4th dimension presents a sagacious challenge to most folks who might be hard fast stuck on the idea of the relativity of time.
Time can certainly be considered in relative terms, but such thoughtful analysis is perspective dependent. Albert Einstein invented a thought experiment to rationalize such relative perspective and at the same time established the universal reality of time as well. Consider you are facing perpendicular to (looking across) the tracks and observe two lightning bolts simultaneously striking the tracts at equal distance down the track. From your peripheral perspective, the two lightening strikes appear to be happening at exactly the same time. But now turn and walk down the track 10 feet or so and repeat the experiment with the lightning bolts hitting the track in the exact place as the first time. This time it will appear to you as though one lightening strike (the one you are now closer to) occurred before the other.
Since the speed of light (in a vacuum) is a constant velocity and space and time vary proportionally, Einstein concluded [and correctly so] that space and time are in essence difference manifestations of the same thing, just as matter and energy are different modalities of the same entity as expressed in is famous equation E=mc2. Using Einstein's mathematical model, astrophysicists ascertained that the universe as we know it began as singularity roughly 13.8 billion years ago. Today, we use this parameter, based on the constant velocity of light, to gauge time in universal terms.
In the lightening bolt thought experiment irregardless of any perspective taken of it in Euclidean geometric terms, the lightening bolts always occur simultaneously from the universal perspective. Time therefore must be real as it is inexplicably tethered to everything else in the universal reality. There is nothing that can be empirically done which will alter the universal time constant and attempting to use relative perspective to deduce differences in the time continuum produces only illusions, errors induced through human cognitive limitation. Time is real and any other perspective of it is simply human sagacious folly.