Quizá/Quizás

Question

Is it interchangeable to say something like
"Quizá mañana entienda más.""Quizás mañana entienda mas."
Just as 'tal vez' and "quizás" are interchangeable, with no fast rules on them, is it the same for using quizá and quizás or is there some guide for when they can/can't be used?
also, is it impossible to use quizá/quizás/tal vez using future tenses? examples:
"Quizá iré a la biblioteca pasado mañana""Tal vez conocerás aquel varón cuando venga""Quizás recibiré una mejor evaluación cuando mejore mis debilidades en mi trabajo"

Answer

Quizá and quizás are synonymous.
I'm not aware of any nuance between them either which always surprises me, but I've asked multiple native speakers and the answer is always the same.
The RAE (Real Academia Española / Royal Academy of Spain) has both in the dictionary, with quizás simply defined as quizá, and quizá containing the definition.
It also explains the etymology (linguistic origin) of the word which I didn't know but I think is wonderful:
Del ant. quiçab[e], y este alterac. de qui sabe 'quién sabe'.
"From the old/antiquated quiçab[e] which is an alteration of [the Latin] qui sabe [in modern Spanish] 'quién sabe'."
So, it literally came from "who knows"!
Who knows where the -s in quizás came from though...

Answer

Thank Gruff! I had no idea it came from 'quién sabe' but that it is interesting.

-Saludos-