Pass Fraud of Railes

There is a simple way to get extra passes and extra-days out of a 30-day rail pass. It was by accident that I discovered this and obtained an additional day. However, when I realized that my memory was not wrong in counting the days but that I had accidentally discovered a loophole, I returned the tickets to the cashier and came home on the last day of my 30-day pass and did not travel 31 days.