In the modern world it doesn't save power, year round most people will turn on lights in the morning just the same, no different in the afternoon. Additionally where you are east to west in the time one will impact you differently. It isn't a one size fits all.
Personally I am not impacted by the clock vs sun, if I'm in my garage my lights are on. Where I'm at we rarely have clear mornings so lights are on, in the afternoon a tree blocks my only west window. Simply put natural light isn't enough.
Alan