Looked around, couldn't find what I was searching for... (Kinda surprised actually as it seems so fundamental)

So, if I understand correctly, .srt files have no "framerate" per se but operate on timestamp, correct? So, my primary question is this: Is the ANY way to determine the framerate from the film from which a downloaded .srt files was ripped? (Like, first-to-last math or something?) This because framerate changers want to know the input framerate and most .srt uploaders do not include this information in their comments.

Barring a definitive answer to that question, an answer to this one will do: Is there a/what is the most common framerate one will find in .srt files uploaded to sub sites? (i.e. "Subscene," et al.) Are they commonly 24 FPS, 23.976 (film), etc.?

Thanx in advance and my apologies if this is just too stupidly newbie of me to ask.