[EA]

Gravity decreases with distance from the Earth’s center. The lower the gravitational potential (the closer the clock is to the source of gravitation), the slower time passes, speeding up as the gravitational potential increases (the clock moving away from the source of gravitation).

[WhyNotHugo]

For an object which is accelerating time passes slower. But an object on a mountaintop isn't accelerating, because the mountain has an upward counter-force.

What am I missing here?