@Dattier You have to rigorously define that. That's not a concept that makes sense. Mathematics has no idea of "time" other than as a variable used to parametrize something.
@Rubio I mean, this is just "general discussion", so pretty much anything is on topic. But I don't think this conversation is getting anywhere, nor is it useful.
It feels more meta than actual rigorous logic. There may be a place where the denizens are able and interested in discussing ... unusual ... premises in propositional logic, but I don't think P.SE is going to be that place.
But "Felix is a live cat" is not a proposition. "Felix was a live cat at 1:00 PM, Sunday, August 27, 2017" is a proposition. But things that change over time are not propositions (unless you include an implied "at the time of this statement").
if you want to discuss this, you can't call it what you're calling it. the words you're using have an established meaning that you're intentionally not using, making this not a meaningful conversation; there's no common language and framework when you're using the same terms others use to mean specific things, but using them in novel and unexplained ways. this is a recipe for frustration and confusion on everyone's part, not the reasoned discourse I certainly hope you were seeking.