Comment by megous

at 1% initial precision of just eg. LM555 itself, you're looking at +-0.5 year just from the chip's contribution. If you ever find 100F 1% precision capacitor and 0% precision resistors, you may maybe hit +- 1 year if the other conditions are perfectly predictable, which they are not.

For your chosen capacitor, manufacturer doesn't even bother providing the tolerances. :) Good luck with that.