Can I get confirmation time from txid (tx_hash)?

Question

I want to get how long it takes time to get first confirmation for each transactions.

My plan is this below.

1. I'm subscribing mempool txes notification from my bitcoind node and I will save it with time.
2. I receive a block generation notification which contains the saved mempool-tx. Then I will calculate the confirmation time. (confirmation time = mempool save time - block notification time)

I have two questions:

1. Do you think that the above way works well?
2. The above way is a little bit hassle. It would be easy if I can get the time by txid. Is it possible? or Do you have any better ideas?

Answer 1

Is it possible? or Do you have any better ideas?

No. You can predict with probability, but you cannot know for certain. Because block generation is a Poisson random event with an average discovery time of 10 minutes.