The Gift Of Restorative Rest

When is predetermined time reached to rest?
Does mind or body know clockwork answer best?
Is a set bedtime always the best way to rest?

A lack of rest plays havoc on both mind and body.
Yet need requires extra night hours worked in emergency.
An art of make up sleep becomes a sweat necessity.

Sleep a strange bed fellow; we all must dues court.
To stay awake for extended periods; is scale battle fought.
To burn candle at both ends frequently; is not wisdom sought.