signs for "on"
space neutral = “on” 
location reference = pointing
3D description = eliminate “on”
on (time) = eliminate “on”
on (holiday)  = “while” 
on (topic) = “regarding”

Examples
space-neutral vs location
They danced on the stage.

3D description
The drink is on the table.

on (time)
I was born on June 28. 

on (holiday)
You will open presents on your birthday. 

on (topic)
We had a discussion on history.