Piece of string question.
First is the meeting needed.
Really is it really needed, will the world end if there is no meeting, will your company grind to a halt, if this meeting doesn't take place, if not then bin the idea.
Otherwise all meeting should have a specified agenda, that should be despatched as soon as possible.
2 minutes probably too short 5 to 20 minutes ideal.
30 minutes stretching it.
An hour or more, what did President Obama say and is the world safe for democracy?