14 day how is this calculated

There are two of us arriving in tokyo 27/3/15 late afternoon leaving Osaka 10/4/15 in the morning. That is 14 days in time but 15 calender days, how is the pass calculated as we need it more so on the last day? if it is on calender days can we activate it on day two in Tokyo. your advice will be gratefully appreciated.
Tonyj