BOSTON (CBS) – We all set our clocks back an hour this weekend. And many of us are still adjusting to the change made four years ago.

Daylight Saving Time was extended into November to save energy.

But Bob in Maynard is skeptical.

He sent us an e-mail and writes:

“I don’t believe there are any significant energy savings when you have to turn lights on first thing in the morning.”

So, is he right?

WBZ-TV’s David Wade reports

It’s like clockwork.

Scratch that.

t is clockwork.

Time to follow that trusty mnemonic: “You have to spring ahead and fall back.”

It’s the end of eight months of Daylight Saving.

Now, even the prettiest sunset comes while Judge Judy is on!

Dark at 4:30!

Why do we do this?

Brookline’s David Prerau knows more about daylight savings than anyone.

After years of studying it for the government he wrote, “Seize the Daylight: The Curious and Contentious Story of Daylight Savings.”

Daylight savings started after World War I.  A couple years ago, the government expanded it by a month, partially on the advice of Prerau.

He says there are fewer car crashes during sunlit evenings and it gets people moving.

“This is a policy that saves energy and basically it’s for free because in addition it gives us these other benefits, reducing traffic accidents, getting people to go out more.”

So how much energy are we saving with this whole deal?

Well, that’s what Congress asked the energy department in 2008.

It did a study and found we save enough electricity per year to power about 100,000 homes.

Other studies say the sudden changes to the clock can cause depression, even heart attacks!

The government thinks it is worth it.

So does David Prerau, who finished our interview with a confession.

“I sometimes forget to change my clock myself because I get very busy during this time period. Of course, I eventually do.”

To learn more about David Prerau and “Seize The Daylight”: CLICK HERE

David Wade