Who can help me calculate how long will I mine Legendary nostr badge on badges.page?

Tried with GPT but I am not sure of calculations and assumptions.

Here's what I have:

PoW settings on badges.page : https://github.com/verbiricha/ngine/blob/main/apps/badges/core/rarity.ts#l23

NIP13 regarding Proof of Work note https://github.com/nostr-protocol/nips/blob/master/13.md

I use Macbook M1 Pro. Mining on Google Chrome uses 24 threads, on Firefox 30.

Epic badge took me about 3-4h to mine (don't remember exactly)