Accepted answers

Question

Just asking out of idle curiosity:
1. What is the longest span of time between asking a question and accepting an answer? All right, that must be the infamous 3:33 question.
2. Between the posting of an answer and acceptance of that answer?
3. Between accepting and unaccepting an answer?

Answer 1

Unfortunately, because of the way accept and unaccept events are stored in the database, these questions cannot be perfectly answered. The problem is that "acceptance" is a special kind of vote, and unacceptance is equivalent to deleting that vote. Because deleted votes aren't accessible, there's no way to check acceptances other than the currently-accepted answer.

For completeness' sake I've checked on both SEDE and the API, and there's no immediately obvious way of circumventing this problem without an unfeasibly expensive query.

That being said, here's what I can answer:

Longest time between asking a question and accepting an answer

At time of writing, the honour goes to Rodger Cooley and Valorum. Rodger asked Which actors from the original Star Trek pilot "The Cage" appeared in later Star Trek media? on January 19, 2011, and Valorum's answer (posted October 10, 2016) was accepted on october 11, 2016.

The total difference, 2092 days, 4 hours, 15 minutes and 45 seconds.

Runner-up is PearsonArtPhoto/Omegacron for What was Shepherd Book's past in Firefly?, with a net difference of 2077 days, 18 hours and change.

Longest time between posting an answer and that answer being accepted

The winner is NiceOrc for answering A collection of stories about young monsters and vampires. The answer was posted on September 21, 2011, and accepted on April 27, 2017. Total difference: 2044 days, 23 hours, 41 minutes and 28 seconds. A nice, patient orc indeed.

Runner-up is geoffc for answering Who is the Hindmost in the Ringworld sequels?. His answer was posted on April 10, 2011, and accepted on October 7, 2016. Total time difference: 2006 days, 18 hours and change.

Longest time between an answer being accepted and it being unaccepted

Because old acceptances aren't stored either by SEDE or the API, this one is unanswerable. Sorry.