Time is endless. There are always 24 hours in a day. Regardless of seeing time as a constant, the length of days does vary slightly, and that is why we have a leap year every four years.
While looking at the events in 2020, there was one that was far less likely to escape from the most attentive watches. July 19, 2020, was the shortest recorded day in the last five decades. It took 1.4602 milliseconds less than the usual 86,400 seconds to create 24 hours a day. But in 2021, the days are getting even shorter, 1.5 milliseconds shorter than normal.
Because the earth is spinning fast on its own axis, since the discovery of atomic clocks in the 1960s, scientists get to know that the planet’s rotation waves vary with the effect of the moon’s gravitational pull, mountain erosion, and catastrophic events such as earthquakes, tsunamis, hurricanes, and volcanic eruptions.