How to delay until a next increment of time occurs ?

[R.Wieser]

David,

> The general simplified idea was run it whenever the time is 0 modulo
> your interval. So you ask how long until that next time.

Ah, using the perf_counter() as its own reference (no "last time fired" 
storage needed).

Thanks for the explanation.

Regards,
Rudy Wieser