Since 1972 there have been 27 leap seconds: additional seconds added to the world\u2019s common clock \u2014 Coordinated Universal Time or UTC \u2014 to account for changes in the Earth\u2019s rate of rotation. Historically, our concept of time is defined as a fraction of the length of the solar day, but as the Earth\u2019s rate of spin is somewhat irregular (slowing and speeding based on various factors) it means solar time and universal time tend to drift apart. So, in order to compensate, we add leap seconds. And this really<\/em> confuses computers. <\/p>\n

I mean, just imagine you\u2019re a computer. You have a very clear sense of time. You know that there are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute: all neat and tidy. Then, on some random day as you await the coming dawn, you watch with horror as your internal clock ticks over from 23:59:59 to the previously-undreamt-of time of 23:59:60. Quite naturally you freak out. Maybe you crash a little, just to calm your nerves. As a result, you take down some of the biggest websites in the world. Everyone gets mad at you. <\/p>\n