The appropriate arrival time will be the one that both the host and the guest have agreed on prior to the finalization of the exchange.
A happy exchange is based on respect and communication. Therefore, we always recommend discussing the possible arrival time that suits both exchange partners before you finalize an exchange. Sometimes an arrival that is too early or too late may not suit your exchange partners and their travel plans - so do not hesitate to address this important issue when discussing all the details of your trip!
Importantly, if your arrival is expected to be late at night due to transportation issues, be sure to inform your host, before finalizing the exchange, or as soon as you are aware of any changes, so that they can accommodate your arrival in their home. In this instance, you might prefer an exchange with a home that has a lock box available for guests.