I have stuck this transaction from 05/20 (6 days now), I don't know why it shows a diferent date (05/24) in "Received time":
https://blockchain.info/tx/d9d901c5e053b4879b61c41cf0f1d0d80c3cf99a10c6ef0650312185edab8c74Can someone tell me exactly when will it be dropped from the mempool? I've heard "72 hours", "4 days", "many days", "a lifetime", etc.
I know there are thousands of bitcoin transactions lost in the limbo right now, I don't understand why this basic info is not available anywhere.
The info isn't available because it doesn't exist.
Not all nodes have the same time for the transaction to be automatically dropped as there isn't really one definitive mempool.
There is a default setting for when a Core node makes the transaction expire though, which used to be 72 hours (3 days). As of Bitcoin Core 1.4, I think that setting has been increased to 2 weeks.
This is a good place to figure out what conditions usually make a transaction leave the mempool.
However, nodes could set their own rules. Your transaction could well stay in limbo for less time or more time than that.
