Final answer:
The privileged motion to fix time to adjourn and the motion to fix the time at which to adjourn differ in terms of who has the authority to set the time.
Step-by-step explanation:
The privileged motion to fix time to adjourn and the motion to fix the time at which to adjourn are both parliamentary procedures that relate to ending a meeting or session. The main difference between the two motions lies in who has the authority to set the time. In a privileged motion to fix time to adjourn, any member can propose a specific time for adjournment, and the proposal can be debated and voted upon by the assembly. On the other hand, a motion to fix the time at which to adjourn is typically initiated by the presiding officer or chairperson, who determines and announces the scheduled time for adjournment at the beginning of the meeting.