playing with tuner cat what does shift time mean

ok i just starting to play with tuner cat there is a table that says shift time in sec VS tps VS shift,performance,low alt??? what does this mean all the cells say 6.38 seconds ??? does this mean that it has to shift in 6.38 seconds or does it shift after 6.38 seconds?? and their is two of these tables low alt and high alt does this altenator i put in a 3600 stall what other tables do i have to look at :confused: