Time is relative in the physical universe.
Relativity and the Einstein Universe
...for us physicists believe the separation between past, present, and future is only an illusion, although a convincing one...
-- Albert Einstein
Time is hard to define. For starters you cannot see or touch it, but its effects are clearly visible. The evidence that we are moving through time is found in everything: our bodies age, buildings weather and crumble, trees grow, etc. The effects of time on our physical surrounding are very real. Apart from that, time is also defined as the fourth dimension of the universe with the other three being space dimensions.
Space and time are involved in a special relationship. So tight that you might wonder whether either of them could exist without the other. This interconnected relationship of space and time is called the space-time continuum, which means that any event that occurs in the universe has to involve both space and time. A simple example of this relationship would be that of two objects that cannot exist in the same space at the same time, they have to be in their 'own' space, or they might occupy the same space, but at different times.
The Einstein Theory of Relativity relates to our physical universe. It notes that time is relative with the speed of the object while moving through space. According to this theory time passes differently for celestial bodies that move at different velocities. This concept is hard to grasp, and even harder to apply to our reality. The main reason for this is that we ourselves are physical beings that inhabit a planet that moves with a fixed speed. Time on earth is therefore linear.
To measure the speed of time you need at least two objects that travel at different speeds. When they reunite time has past differently for each object. The closer the speed of an object gets to the speed of light, the slower the time in that object passes compared to another object that remains 'stationary'. The concept here is that time is not linear, but relative. It indicates that our day-to-day perception of time, is different than its real nature. However, the circumstances needed to observe, proof and 'benefit' of this real nature are 'extreme' and have not yet been accomplished.
The one circumstance that we know that affects the behavior of time is the speed of the physical object in the universe. However since it is proven that time is relative, it might also be possible that its relativity depends on more variables than just 'movement of the object'. Also, since movement has direction (there are three space dimensions) is seems conceivable that time itself has direction too, or could even curve, bent, fold, twist etc.
Einstein's theories about time and relativity are based on the existence of a physical universe. To be able to measure time you need to have physical objects (matter, mass) that move through space. These objects generally suffer the effects of time (aging). Further to that there seems to be a need for consciousness in order to have a notion of time. Therefore, to measure the passing of time it seems that you need matter, movement and consciousness. What would happen to time itself if one of these basic entities is taken away? Is time maybe a result of interaction of these entities?
As a comparison we could look at other entities that are the result of movement: An induction electric current for instance is the result of the movement and interaction of objects with certain characteristics. Without objects or movement, induction electricity does not exist. It gets only generated under special circumstances and disappears when the conditions needed cease to exist. It is not an absolute static entity that always exists but a derived one.
The question is: if you cannot measure time because one of the key entities is missing, whether time itself continues to exist, time might be generated and only exists as a consequence of interaction between matter, movement and consciousness.
Universal rules determine how time applies to physical objects that move through space. However, there are no definite rules about how it would apply to pure non-physical entities. Imagine a free, unattached, independed consciousness, that can move through space and interact with the physical universe, but without having mass or body (God, angels, spirits). A discussion regarding such entities might be useless as we cannot proof that they exist. If they would exist however It would be hard to determine and imagine how time would affect such entities.