Time is a conception that the mind extracts by realizing the emergence of events. Thus, when we speak of time, we’re not talking about any extra-mental existent. Rather, what exists extra-mentally are those events, and through their sequential emergence the mind conceives of time.
For example: when we observe the sun setting, then rising, then setting again, we call this sequence of events a “day”. When we observe the moon going through all of its phases, we call this sequence of events a “month”…. and so on, and so forth.
And so, if nothing emerged into existence, then it would be impossible to extract the concept of time from the world.
If X exists and Y emerges into existence, then we can say that X’s existence precedes Y’s.
If this X also began to exist, then we say: X’s precedence with respect to Y is a temporal precedence (Qablia Zamania). Thus, X and Y are both part of time, since “time” here refers to the sequence of all events, and both X and Y are events.
If this X did not begin to exist, then we say: X’s precedence with respect to Y is an essential precedence (Qablia Dhatia). Thus, X is said to be timeless, whereas Y is part of time (since Y is an event, and X is not).
Time Before the First Event
From the above, it becomes clear that there was no time before the first event.
Claiming that there was a time that preceded the first event, is tantamount to claiming that there were events that preceded the first event. In that case however, the first event would not be the first event, and that is absurd.
This however, does not preclude the existence of a necessary being that essentially precedes the emergence of the first event (it in fact entails it). Since a necessary being would not be an event, and there is no harm in supposing the existence of a non-event, preceding the first event.
 Event: something that began to exist.
 Contrary to those who conceptualize time to be a sort of box that permits the occurrence of changes within it. Such that concepts like “before” and “after” are only meaningful inside of this box, and completely meaningless outside of it.
There is no proof for the existence of such a box.
 This is not a sufficiently inclusive definition for precedence. Obviously, if X exists and then ceases to exist, and afterwards Y emerges into existence, then X’s existence is still said to have preceded Y’s.
 By “timeless” we mean nothing more than changeless. This is because X is beginningless, whereas that which changes is necessarily emergent. More on this here.