But don't we already have this problem? If, for example, I wanted to calculate exactly how many seconds old I am, I would probably do it the naive way, adding up the years, months, days, hours, etc. But to get the truly exact answer, I'd also have to look up how many leap seconds occurred during my life, making the calculation roughly just as complex. Or I could not bother and just report the result in "civil" seconds, which are slightly and variably longer than "atomic" seconds. If I cared enough about the difference, I probably would be using a true atomic timescale (without leap seconds) anyway.
If you were born before 1972, it's impossible because that's when UTC became reality. And really, do you think you know the time of your birth to within, say, 35 seconds (which is the number of leap seconds you have to add)? Do you think the clock at the hospital was accurate to within 35 seconds?
>that occurs once every few years and _surely_ everyone would have prepared and tested for.
yeah... like y2k, ipv6 and the US conversion to the metric system!