Time proven to tick faster on Tokyo Skytree than on the ground www.japantimes.co.jp

A Japanese team of researchers has shown that time at Tokyo Skytree’s observatory — around 450 meters above sea level — passes four nanoseconds faster per day than at near ground level.
On a weekly average, the clocks showed that time runs four nanoseconds faster per day at the observatory than near the ground.
The researchers made the optical clocks insensitive to temperature changes, vibrations and electromagnetic fields.
Performing a stringent test of Einstein’s theory requires either a very precise clock or a large difference in height.
Outside of the laboratory, the best tests have so far been undertaken by satellites, at altitudes that are thousands of kilometers apart.