Recently there was a big fuss (including denouncements from many I know) over a U.S. effort to do away with the leap second. People claimed this was like trying to legislate PI to be 3.I am amazed at the leap the the defense of the leap second. I would be glad to see it go. All our computers keep track of time internally as a number of seconds since some epoch, typically Jan 1 1970 or 1980. They go through various contortions to turn that absolute time into the local time. This includes knowing all the leap-day calculations and the leap day calculations. It’s complicated by knowing that sometimes the day is Feb 29, and by knowing that a very, very few minutes have 61 seconds in them (or if you prefer, that a very few hours have 3601 seconds and rare days have 86401 seconds.)

That’s a mess. A minute should always have 60 seconds. Special casing all time code to deal with this was the wrong approach, and as noted, is subject to errors because the code is very rarely tested in that state.

I’m astounded to see people saying this is the same as declaring pi to be 3. It’s having 86400 seconds in most days and rare leap seconds that is the integerization of a real number. The truly scientific approach would be to declare the day to be 86400.002 seconds, and lengthen that number over the centuries, would it not?

Astronomers, like computers, can and should keep track of time as an absolute number of seconds since some epoch. They actually care very little about what the local time is other than to know when it’s dark, something leap seconds have insignificant bearing on. Indeed, astronomers might be happiest using siderial time (where a day is 23 hours 56 minutes and +4.1 seconds, the true rotational period of the Earth.)

Our system of time is not one scientists would pick in the first place. It is clearly designed for the convenience of the ordinary people, and the legacy of the traditional means of telling time. It’s silly to use this legacy system and at the same demand the general public and its timekeeping systems jump through error-prone hoops to make it reflect noon correctly to the second. Nobody even uses local time anyway, they all use a time zone. The time zone is off by a huge margin from local time, why does it matter in the slightest if it’s off by a few more seconds?

In many centuries, the drift will be noticeable. If we still care about local time, we can fix it then.