You thought Daylight Saving Time was a problem ...

 ... wait until we have leap hours!

If you're reading this, it's not likely you will ever see a leap hour but since the leap second was recently abolished, scientists are debating what to do with all that extra time. 

The average year is really 365 days, 5 hours, 48 minutes, and 45 seconds. Thus, we have leap years. (Wikipedia: Tropical Year) But each year is different and so additional fine tuning was required which is how we got leap seconds.

The leap second was introduced to reconcile different time scales: one that was defined by atomic clocks and the other that measured the actual rotation of the Earth. (Wikipedia: Leap second) There have only been 27 leap seconds since 1972 when they were first implemented. But leap seconds caused problems. For example, midnight does not occur simultaneously around the world. The leap second in Japan would not occur at the same time as a leap second in the United States. In 2015, the leap second caused interruptions with Twitter, Instagram, Pinterest, Netflix, Amazon, and Apple's Beats1. The Intercontinental Exchange (parent body to clearing houses and stock exchanges) ceased operations for 61 minutes at the time of the June 2015 leap second.

One proposed alternative to the leap second is the leap hour. Fortunately, this would only occur once every few centuries meaning I'll never see one as the leap second was only abandoned a couple of weeks ago. A leap minute is also possible which, if you're young enough, you might see in about 50 years. But think of the problems a leap hour or a leap minute would cause. 

Although there would be plenty of time go figure out how to implement the leap hour or leap minute, another option is to update the definition of a second altogether. Currently, the second is defined as 9,192,631,770 cycles between two energy states of caesium atoms exposed to microwave radiation. (The Economist: The second may soon be redefined, October 21 2026)

Easy for you to say. 

Scientists are now developing clocks based on different chemical elements which can measure time more precisely than caesium clocks. Metrologists (not meteorologists) are scientists specializing in the science of measurement. They have given themselves until 2030 to redefine the second.

Stay tuned. Only time will tell.