The Panama Canal is 77 km long, and is divided into three parts, which means that during each transit, the ship will go through 3 locks - because the middle part of the canal is above the sea level. So a huge portion of the time is spent waiting in the lock to adjust to the hight of the lake in the middle of the canal.
The time to pass it is around 6 -8-10 hours - second option is the best