to stretch or extend intentionally

延ばす(のばす)	(VT) To lengthen or extend (the life of a sick person)(the deadline) (your stay in a hotel) also, to procrastinate. More used with time. $$$

伸ばす(のばす)	(VT) More used with things. Stretch your back, extend a collapsible umbrella/telescope/admantium claw.