Well not so ... I looked closer at the article.
There are "Limits".
Consider a period of time after either midnight or midday and describe that as being AM or PM. Halve that time and there still is a time AM or PM.
Continue halving that time and it is still either AM or PM. Eventually that amount of time will approach zero and we have a notional 12am or 12pm being effectively real.
Differential calculus is how we engineer aircraft or build Plaza Premium lounges.
