Check my availability on Google Calendar.
“Private tour” is literally a private tour, so sorry there is no room for more booking. But please take a look at the number above the tour name, it is the number of vacant seats for the upcoming tour, which is already booked by whom wanting to go on the tour. If you apply for the existing tour, you would share the seats with other participants but also share the basic charge, so you can enjoy the tour at a cheaper price!