Accumulated difference between UTC without leap seconds and UT1 Currently UTC is maintained within 0 9 s of UT1 by the addition of leap seconds If we no longer add leap seconds how long will it take for the difference to accumulate to an appreciable amount of time It is my understanding that TT was formerly known as Ephemeris Time and that therefore the difference between TT and UTC currently about 65 seconds represents the leap seconds added in the last hundred years or so If we had not added those seconds our clocks would now be fast by that much I would not consider that approximately one minute is significant to non astronomers We set our clocks as we are told to and live according to them The apparent sun varies plus or minus 16 minutes or so because of the Equation of Time anyway And few of us live exactly on a time zone meridian and so our clocks do not even show Local Mean Time in the first place So keeping our civil clocks in sync with the Sun is not an issue at present How many years before it could become an issue in that 0 hrs on the civil clock the beginning of the calendar day would no longer be in the middle of the night It would be inconvenient to begin a new calendar day during the daylight hours when most of us are already at work As near as I can figure out if we stopped adding leap seconds it would take about a thousand years before UTC would be 30 minutes different from UT1 Is this correct If not then how long would it take If it would take many thousands of years for difference between time and apparent sun time to accumulate to the point where it becomes inconvenient for most of us then that fact should be made clear in the article when discussing the Pros and Cons of dispensing with leap seconds