That rather depends on where your readers are in the world relative to you.
It would be very nice (AWA *pretty pretty pur-lease* B^>) to have at least a "show these ads only in/out of local working hours" or "boost/drop my CPC/budget in/out of local work hours" at (say) an ad-group level to roughly capture the local work/non-work clicks following the sun.
AFAIK there is no penalty for enabling/disabling during the day, though presumably the budget computations and automatic ad pacing get more tricky for all parties concerned...
Rgds
Damon