The Associative Laws say that it doesn't matter how we group the numbers (i.e. which we calculate first) ... ... when we add : (a + b) + c = a + (b + c). ... or when we multiply : (a Ã b) Ã c = a Ã (b Ã c).
To complete the PCT in two months (or less) you will need to average approximately 43.6 mi / 70.2 km per day (this was my longest day on trail).
In brief: 48 to 72 hours. The actual placement of the TB skin test (PPD) only takes a few seconds and should be painless. However you need to return to the clinic to have the skin test read by someone who knows what they are looking for between 48 and 72 hours later. In brief: 48 to 72 hours.