I think that it is most likely that this phenomena is psychological and doesn't indicate time accelerating.
As for measuring time acceleration, perhaps comparing time on earth to time on the event horizon of a black hole and seeing if they deviate by a different amount than predicted by the present mathematical models it would be useful for uncovering any acceleration of time. Assuming the acceleration of time was exponential then the slowing of time on the event horizon would lead to a different rate of acceleration than on earth. Evidence of that difference could prove the theory.
As for measuring time acceleration, perhaps comparing time on earth to time on the event horizon of a black hole and seeing if they deviate by a different amount than predicted by the present mathematical models it would be useful for uncovering any acceleration of time. Assuming the acceleration of time was exponential then the slowing of time on the event horizon would lead to a different rate of acceleration than on earth. Evidence of that difference could prove the theory.
Yes/no? Thoughts?