Question: Is the prophecy on the Three Days of Darkness accepted by the church? Could you explain it and what it really means?

The Three Days of Darkness is a private revelation and should hold no more weight in our hearts and minds than that. Too many people get caught up in all sorts of mystical, private revelations and experiences and then live in fear or confusion. The Three Days of darkness deal with events occurring around the time of the return of Christ. I wouldn't take much stock in these kinds of things. Let's remember what is actually important: if you are right with Christ (meaning: in as sate of sanctifying grace) when the end comes, then you will be saved. it doesn't really matter whether that "end" is the end of all time on Earth at the Second Coming, or if you get hit by a bus today and killed. So live for Christ each day and be focused on His grace and guidance for today and don't worry about what might happen at "the end". As Jesus told us in Matthew 6: 34 "Do not worry about tomorrow; tomorrow will take care of itself. Sufficient for a day is its own evil."