The Earth’s diverging timescales — GMT, atomic, GPS, and Coordinated Universal — are the subject of increased scrutiny as the possibility of catastrophic temporal reconciliation events increases:
Unbeknown to most people there is not a single accepted way of telling the time, but several different scales running concurrently. The differences are usually small, but the scales can be as much as 30 seconds apart and the gap between them is growing steadily.
Aircraft navigation systems tell a different time from the watches of passengers, pilots and air traffic controllers. Experts are warning that this could spell disaster…
“We should only have one type of timescale throughout the world,” says Bill Klepczynski, a time expert who advises the federal aviation administration. “There’s a possibility for danger…”
The problem arises because the Earth cannot keep time as accurately as modern atomic clocks, which count the steady shaking of atoms. These atomic clocks replaced the motion of the Earth as the world’s official timekeeper in 1967. The pull of the moon is gradually slowing our planet down, so every now and then our clocks are halted for a second to let it catch up.
(via Interconnected)