Too Much Time On My Hands

A little Styx for you there. Think you just don't have enough time? Well, you'll have no excuse come December 31st when the day will be one second longer.

Like the more well-known time adjustment, the leap year, a "leap second" is tacked on to clocks every so often to keep them correct.

Earth's trip around the sun - our year with all its seasons - is about 365.2422 days long, which we round to 365 to keep things simpler. But every four years, we add 0.2422 x 4 days (that's about one day) at the end of the month of February (extending it from 28 to 29 days) to fix the calendar.
Likewise, a "leap second" is added on to our clocks every so often to keep them in synch with the somewhat unpredictable nature of our planet's rotation, the roughly 24-hour whirl that brings the sun into the sky each morning.

Use it wisely.