That doesn't seem to be the case, at least for UTC. (Do scientists use a special calendar that reflects Leap Seconds more quickly?) http://datacenter.iers.org

That doesn't seem to be the case, at least for UTC. (Do scientists use a special calendar that reflects Leap Seconds more quickly?) http://datacenter.iers.org/eop/-/somos/5Rgv/getTX/16/bulletinc-049.txt http://datacenter.iers.org/eop/-/somos/5Rgv/getTX/16/bulleti... "Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every six months, either to announce a time step in UTC or to confirm that there will be no time step at the next possible date." (That said, saving them up until the next Leap Year would mean a maximum discovery-to-implementation interval of 8 years, rather than the current 1 year max.)