I'm already using this timestamp technique on my website and so far no bot operator has bothered trying to work around this. However even if some bot operator w

I'm already using this timestamp technique on my website and so far no bot operator has bothered trying to work around this. However even if some bot operator were to specifically target a website using this technique and try to decrease the timestamp, I believe you could still force a bot to wait by just changing the website to use something like a cryptographic nonce that includes a timestamp instead of just a simple timestamp that can be understood easily.