option + drag front of scene to move start point

(hold the, option key, when dragging the, front of a, scene to move start point, forward or backward in time)

 

Scenes don't have start points for that to be an option, only length.
They start where another one ends, that's why you can only change the end of it by dragging, technically changing the length/start point.

Clips have both, so both start and end is draggable with a mouse (no need to hold modifier keys) this is possible because unlike Scenes Clips are free on the timeline aka linear.

 

I figured if we could do it now with both clips and patterns, why not scenes too?

what if you only wanted the second half of your scene?