[ByteMercenary]

After thinking about changes to the length of a day on any planet, I am inclined to suspect the measuring system in use rather than any change in the rotational velocity of a body as huge as a planet. I mean, you are talking about some seriously huge forces that need to come into play when discussing a change to the inertial forces involved. But errors introduced while setting up and operating the measuring system could easily produce data that is a tiny bit random.

JMHO ...

[Magnum44]

The article makes sense. If the rotation rate is slow, as compared to Earth, variations in the rate will be of longer periods. The Earth spin rate also varies, but its measured in fractions of seconds. However, Earth spins faster and spin provides a stability of its own.

In both cases, the variations can be caused by fluid cores. Think if spinning two eggs on a counter top, one raw and one hard boiled. The hard boiled eggs spins at a near constant rate. The raw egg will have a lot of wobble.

[Steve Van Doorn]

Both of your arguments of valid. The margin of error and liquid in side the mass. I lean toward magnetism of the system primarily the sun and the moon. Look at the how the magnetism of the moon moves our oceans giving us tides. Those magnetic waves likely effect the interior of our plant as well.

With the magnetic pole shift coming we should see some very interesting events taking place never seen before in written history.