Usually, the event organisers are setting the matchmaking agenda as follows: one 1 to 1 session in the morning, and one in the afternoon, with a lunch break in between.
The only inconvenience about this approach is that participants don't have enough flexibility in case they want to attend a particular time-slot in, let's say, the morning session. If the morning session start at 10 o'clock and lasts until 12 o'clock, the participant might be available for two meetings only, not for the entire session.
That's why we created the time-slot preferences selection.
The participant can now choose their preference for the sessions' time-slots.
The organiser just needs to create the time-slots as they would create matchmaking sessions.