Original sentence: At the foot of the shaft the visitors begin a guided tour through the main gangway of the mine and stop at various points to discuss different aspects of the anthracite mining industry.The tour concludes where the miners ended their final days within the mine.The tour is open seven days a week from April 1st to November 31st and is closed only on Thanksgiving Day
Edited sentence: At the foot of the shaft the visitors begin an hour-long guided tour through the main gangway of the mine and stop at various points to discuss different aspects of the anthracite mining industry.The tour concludes where the miners ended their final days within the mine in November 1966.The tour is open seven days a week from April 1 to November 30 and is closed only on Thanksgiving Day