Bringing a meeting to a close happens in three very distinct ways depending on exactly what else is happening on the floor at the time.
Even if you are making a heavily privileged motion to abruptly end the meeting, you cannot literally interrupt another person who is speaking. You must wait for them to finish, seek recognition from the Chair, and only once recognized can you move to adjourn.
Use this when the agenda is complete and there is no further business to bring before the assembly.
Use this when no motion is on the floor and the assembly wants to end the meeting before the next item is taken up.
Use this when debate on an item is already underway and the assembly wants to stop business and end the meeting immediately.
About 10 to 15 minutes before the expected end time, name the situation clearly and give the assembly a choice. For example: “We are approaching our scheduled end time and still have three items left. Is there consent to extend for 15 minutes, or would the assembly prefer to adjourn and carry these items forward?” If the group does not want to extend, the meeting should adjourn using the appropriate procedure for the moment.