I looked this up last night out of curiosity. For a ship traveling 10 knots it takes 17 days. If the ship has to go around Cape Horn it is 52 days. I'm sure a decent amount of those ships are pan-max and would require the horn passage.
I'm not sure how they calculate the canal passage, but multiple websites claim it only takes 8 to 10 hours to travel the 50 miles.
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