Scientists at the National Physical Laboratory in England observed the shortest day on June 29 and on July 26
On both of these days, the Earth completed its rotation in less than 24 hours. It was 1.59 milliseconds noted on June 29 and 1.50 shorter time noted on July 26
Climatic changes such as melting and freezing of glaciers, whose shifting weight pulls on the earth, The New York Post reported
Earthquake and other seismic activity which moves mass toward the centre of the Earth like a spinning person pulling their arms in, The Guardian reported.
Movement within the Earth's molten core that shifts mass on the planet, Forbs reported
Ocean circulation and pressure on the seabed that pulls on the Earth's axis, ABC reported.