No leap second is scheduled for the end of May.

The last leap second was added on June 30, 1997.

Between 1972 and 2012 a leap second has been inserted about every 18 months, on the average.

June 30 - An extra leap second is added at the end of the month.

December 31 - An extra leap second is added onto the end of the year.

It would seem that time is running out for the leap second.

Some time in the 22nd century, two leap seconds will be required every year.

What's in question is the fate of the leap second.

A leap second has been added 15 times since 1972, most recently on Dec. 31, 1987.

It never generates a time that is during a leap second.