Timing Your Presentation or Online Class.

When giving a presentation or teaching a class (virtual or in-person) start out with a clear idea of the time allowed. 
Start with a draft of the material you plan to cover. Create bullet points for the key ideas.
Decide what material will be conveyed via slides, and calculate the number of slides you’ll need.
Speak it through and time yourself. You will most likely need to shorten and edit.
Once your presentation or class fits the allotted time, create a timeline. {Slide #1: 3pm -3:04. Slide  #2: 3:04 pm – 3:07.}
If questions or a discussion will be part of the session, make sure you deduct that time from your presentation to remain within the overall time allowed.
Before you begin, have your timeline in front of you and start the stopwatch function on your phone. 
Make sure you hit each stage on your timeline at the correct point. 
It takes discipline to stay on topic and in the allowed time, but you will convey leadership and professionalism.
And, your listeners will thank you.