I know in audio engineering they run into this issue frequently. Something to do with Nyquist? I don’t know. But it’s that point where the two entangled parts meet up and you’ve just shrunk the time part as close to 0 as you can go. Something something about Dirac delta function is coming to mind too.
The “instant” is the thing I’ve been studying on and off for years but you think I could come up with a coherent sentence about it.