Defending your PhD thesis is mainly a ceremonial affair. In that ceremony, I will be questioned about my dissertation by a committee of academics. Throughout the question round, I am supported by my paranymphs. This part is the actual thesis defense, and I would love it if you were able to join for this (do not worry about the number of spots: there are always plenty).
After 45 minutes, the beadle (a kind of master of ceremonies) enters. They call out "Hora finita," which means that the questioning is finished. At that moment, the committee, my paranymphs, and I leave the room. A little later we will all return, and I will officially receive my degree.
The second part of the day is the reception: this is a small get-together held in the academy buildig itself. Usually, a significant part of the reception is spent standing in line to congratulate the recent PhD graduate and having a few drinks. After that, there is possibly a short speech by someone from the institute. The reception usually lasts about an hour. After the reception, there is a dinner for people travelling in from afar and people involved in the ceremony, and we will end the day with the party. More about that later!