My Bitcoin transaction still unconfirmed since yesterday and I paid a fee of 120sat/bit. Yesterday later I did other transaction that was confirmed in 1 hour (same fee). How many time can it still unconfirmed?
Pay around 180s/220s p/TX and it will probably be confirmed in the next block, that's my experience. Like other people said, if you use blockchain, just send a little more then what is required to get into the first block, and you should be good.
Transactions with low fees at the moment will either confirm overnight, or not at all.
Here you can see how many tx are waiting to be confirmed,
https://blockchain.info/charts/mempool-sizeAnd here is the avg fee for current tx's.
https://bitcoinfees.21.co/