On both our in season and off season 2 day tours, the climb to the summit is spread out over two days.
During the in season, on day 1 we will hike about 6 km to our lodging for the night (3,400 meters) in about 6-7 hrs. From here to the summit on day 2, it is about a 1 1/2 hr. climb and the descent to the 5th station tends to be 3-4 hours.
During the off season, on day 1 we will hike about 4 km to our lodging for the night (3,000 meters) in about 3-4 hours. From here to the summit on day 2 it is about a 3-4 hour climb and another 3-4 hours in descending back down to the 5th station.
These are just approximations, as the time it takes to hike up and down Mt. Fuji varies from group to group.