As if you don’t already have enough trouble getting up in the morning, Daylight Saving Time is starting three weeks early this year. The reason: more daylight in the evening will save the U.S. 100,000 barrels of oil a day.

Or will it?

The change moves sunrise and sunset each an hour later, shifting an hour of daylight from the morning to the evening. That means you’ll need one hour less of lighting each night which could translate into savings on your energy bills. At least that’s the rationale behind the clause of the 2005 Energy Policy Act which extended Daylight Saving Time by three weeks in the winter and one week in the fall.

But will the extra Daylight Saving really mean savings on your energy bills for the three weeks in question? For some, it may. For many others, I expect the change will have no impact or end up costing more in the end. Here’s why:

Why An Early Daylight Saving Might Cost Your More

• That extra hour of daylight isn’t coming from nowhere. No act of government can lengthen a day. All that’s happening here is that an hour of morning light is becoming an hour of evening light. So instead of having your lights on for an extra hour each night, you’ll simply have them on while you’re getting ready for work each morning.
• Schoolchildren in the dark. With sunrise pushed back so late, some kids may be waiting at their bus stops in complete darkness. You can bet a lot of worried parents will either wait there with their gas-guzzling SUVs running or simply drive them in for a few weeks.
• Software reprogramming. You Microsoft Windows users out there likely received a software patch for the earlier Daylight Saving start without realizing it, but Microsoft probably spent a good bit of money putting that patch together. Likewise many other computer systems will require adjustments to their calendars, and those adjustments often come with a hefty price tag for software makers.
• Schedule changes. Some businesses will have to alter their operating schedules to compensate for the earlier change in daylight. Airlines have already complained that flight rescheduling will cost them millions.

Ignoring all of these factors, and assuming you use the same amount of lighting in the morning that you normally do, how much can you expect to save thanks to an extra hour of evening daylight for four weeks? Not much. Let’s do the math, assuming you have five 60-watt light bulbs you regularly use every evening:

28 days * 1 hour * 5 light bulbs * 60 watts = 8.4 kilowatt-hours (kWh)

Using the average residential cost per kilowatt-hour of 10.22 cents from November 2006, here’s how much you’d save:

8.4 kWh * $0.1022/kWh = $0.86

So after an act of Congress, millions spent in computer reprogramming and schedule adjusting, and kids waiting for buses in pitch dark, you can expect to save 86 cents a year thanks to the extension of Daylight Saving Time. And if your house already made the switch to energy-saving CFL bulbs like we did, cut that savings to 19 cents.

I feel richer already and Daylight Saving doesn’t even start until Sunday.