whats the timing for when the clock starts and ends on killer (like does is it start when you take control of the killer ? )

"Starts when the black bars (top/bottom) disappear.

• Ends when the last hook bar next to the player's name disappears.
• If the last survivor is killed with Memento Mori or a similar ability (Finishing Mori, Killer Power), time ends when the "kill" bloodpoint score event appears (top right)."