Unless there are solid Biblical or dogmatic statements stating otherwise, we have no reason to believe that time doesn’t exist in the afterlife. The biggest problem here is that people tend to get Eternal Life confused with Infinity. Generally, one could say that there are three “tiers” to creation’s relationship to time: Temporal (has beginning and end), Eternal (in this case, has beginning, but no end), and Infinite (beyond time).
Even in the afterlife, God, Christ, and Paraclete alone will be Infinite. The rest of us will “just” possess eternal life.
I’d even argue that the Bible has solid evidence against the prospect of us transcending time, as Matthew states:
“But about that day and hour no one knows, neither the angels of heaven, nor the Son, but only the Father.”
How can the Angels and Saints simultaneously be at the Final Judgment and not know when it’s going to happen? How can we, as saints, exist at the very moment that these prophecies will be fulfilled, and yet lack the capabilities to sense the precise time or find a nearby calendar? There has also been no indication that Heaven has since been “briefed” on these matters.
While these are perhaps less reliable than the concrete statements I made earlier, it is also important to note that everyone who has claimed to have visited Heaven through a mystical or near death experience was able to chronologically list the activities therein. Some may express uncertainty over how
exactly long they were there, none of them expressed any doubts over the existence of time there. With that said, time doesn’t seem to behave the same way up there (according to private revelations).
One man in particular claimed that 3 days on Earth would equal exactly 15 minutes in Heaven, which is consistent with people who have claimed to have been in Heaven for mere seconds before returning back to Earth minutes to hours later.
Edit: For reference, when I refer to “Eternity”, as it pertains to humans, I am referring particularly to Eternal Life, which differs in nature from God’s inherent Eternality. The word “eternity” doesn’t just mean without end, but without beginning too, however, we know that humans don’t possess this type of eternality since if we did, that would mean that the Apostles would simultaneously exist before and after Adam and Eve, for instance, which makes no sense. Holding the belief that humans have God’s inherent transcendent eternality also means that, before Abraham was, Padre Pio would be, which, if true, invalidates the very point that God was making when He made that statement.
Perhaps, when considering a saint’s relationship with Heaven, and the afterlife, it would be safe to assume that we haven’t transcended, but rather, “mastered” time. This belief is more consistent with the Scriptures and abundance of Private Revelations.