It’s a fun wink and one that suggests this isn’t some temporary gimmick created by the universe to improve Nyles and Sarah as human beings; they’re trapped in a temporal loop by something that has existed since dinosaurs walked the earth and potentially much longer. It’s fair to wonder if the time loop is as old as the planet, if not the universe, with these gentle giants roaming the same plains for eternity. But you know what? Good for them! When you think about it from the dinos’ perspective, Nyles and Sarah are throwing away the gift of eternity like suckers.
We of course don’t see Nyles’ first day in the time loop—and we may not have seen a moment from even his first million. It is intentionally vague how long he’s been trapped in this time loop, but certainly years and probably decades have passed when the film begins. Refreshingly breaking from the formula established by Groundhog Day, we as viewers have skipped the early sense of exploration, the subsequent gleeful anarchy without consequences that follows, and finally a brief nihilistic despair. Rather we meet Nyles after he’s come to a happy resignation toward his fate. Hey, at least he gets to wear the same shorts and Hawaiian shirt each day and either aid or subvert the wedding he’s attending however he chooses.
We can be pretty sure that it’s been ages since it began because he already knows about everyone in town, from his cheating girlfriend to the deal about the local barflies. In a pinch, he can even call on a memory about the bearded hermit still pining for the woman who took his virginity when he needs to steal the dude’s car. Plus, as he tells Sarah, he first met J.K. Simmons’ Roy in the “early days” when he was still exploring the wedding’s guests and probing them with a sense of curiosity. Hell, he was even still wearing a suit in those before times.
If those early days were actually early years, then many more must have passed since then. Whatever the case may be, we can deduce that on the original day zero, he must’ve come into this desert after there was a morning earthquake which opened up the cave hiding a time paradox. I’d speculate it was at night after the wedding—perhaps he even was on a drunken bender after discovering Misty (Meredith Hagner) was cheating on him? In any event, he entered the cave and I’d guess the next 40 or 50 years remained much the same ever since… just long enough for him to forget what he even did for a job in the way, way back.
While we only discover Roy’s full story late in the movie. Roy is a man who married (or remarried) late in life and started a family even later. But despite all that time to reflect on the transience of existence, he still was missing his early wilder days when he made a fateful drive from Irvine down to Palm Springs, California. He’d regret it.