The notion of a ‘present moment’ (nunc stans) requires a structure of presentation, at the very least, a minimal condition of reception.
In order for it to be a logically meaningful concept, negation is required, momentariness not present.
So, the concept has an implicit complexity, automatically calling on notions of ‘past’ and ‘future’, in its very articulation.
The notion of the present is thus an anticipatory conceptualisation directed towards the assumption of an event. An event is a distinct, or distinguishable, temporal object, or objectification, the multiplication of which suggest the sequences constitutive of temporality. Whether as ‘internal psychic states’ or ‘external transitions between events’, ‘temporality’ is supervenient on both of these factors.
Imagine a universe, in which nothing at all happens. Would it be at all reasonable to speak of temporality with regard to such a universe? Temporality, or at least temporal conventions as commonly understood, simply would not obtain in such a universe.
Therefore, temporality or time is intrinsically tied up with objectification, with the determinate objects known as ‘events’. Events, or eventuality, more generally, are/is bound up with general and localised determinations of process.
The notion of the ‘eternal now’, is a standpoint ‘apprehending’ eventuality, ‘as a whole’, but without any form of localised grasp. Therefore, such an infinite apprehension cannot be so easily communicated in the language of localised processes and their semantic conventions.
This is not merely a theoretical supposition.
At the speed of light, there is no time. So, for a bunch of photons whose journey begins with the hypothesised onset of the so-called universe, nothing at all has happened. Light is alleged to be a ‘physical’ property, but that property arises from its interactions with other processes and events, a subset of considerations of which constitute the concepts of physics. But those very concepts indicate a quite specific ‘timelessness’, that can be ‘seen’.