The clocks were wrong.
He was certain if it. Each minute was taking longer than its normally allotted sixty seconds. And he would prove it too, if only he could find a single correct clock to reference.
Though proving it, he knew, would be just the beginning. He would then need to figure out who broke all the clocks in the first place, how they did it, and, most importantly, why? Surely an issue of such magnitude as this couldn't simply be an accident. And yet, for what purpose would someone intentionally mess with the flow of time itself?
It wasn't just about the clocks, you see. The actual pace of time seemed to have shifted just ever so slightly. And it would be much easier to figure out the whos and hows and whys of it all if he could first convince someone—just one single person—that he was correct.
Naturally, no one believed him.
"You've had too much coffee," his co-worker advised him. "It's got you all wound up. Switch to decaf."
In truth, he hadn't had any coffee in over a month. He'd already sought to rule out caffeine as a culprit to altering his perception of time, and mostly stuck to plain water while trying to sort this problem.
"When's the last time you had a vacation? Take off somewhere for a week. You'll come back complaining the clocks were too fast."
Indeed he'd thought of that too. Perhaps he was overworked, and merely needed some time to unwind. And so he requested some time off in the following month, and resolved to spend that time purely recreationally. For time, as everyone knows, flies, when one is having fun.
...But time did not fly. The clocks were still wrong.
He could not put into words precisely how he knew this. Were the tick, tick, ticks of the second-hand spaced just slightly too far apart? Was the sun hanging in the sky just slightly too long? Whatever the case, it was, to his mind, an incontrovertible fact:
The clocks were wrong.
Why was it that only he could sense it? How had everyone else so easily settled into this new, slower pace of the universe, yet he alone could tell that it wasn't correct? Was there really not one other person, among the billions living throughout the entire planet, who believed in the error of the clocks as he did?
"Yes, sir. The mission is proceeding as planned."
"And what of the time dilation issue?"
"Well sir, we were unable to completely eliminate the effect, but we've at least managed to reduce it to the most imperceptible levels. It should be impossible for anyone on Earth to notice."
"Excellent. Continue with your work."