We'll have a leap second at the end of this month. The last minute will have 61 seconds. But, not without controversy:
From Cosmos Magazine:
The leap second has long caused debate among member countries of the International Telecommunication Union (ITU), with some arguing for it to be abolished in favour of the exclusive use of atomic time.
Every time a second is added, the world's computers need to be manually adjusted, a costly practice that also boosts the risk of error.
High-precision systems such as satellites and some data networks will have to factor in the leap second or risk provoking a calculation catastrophe.