BOSTON (CBS) – It’s almost time to set the clock back.

The official change to standard time occurs at 2 a.m. Sunday, though most folks will change their clocks Saturday night.

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The National Fire Protection Association also reminds people to change the batteries in their smoke alarms and carbon monoxide detectors.

Some states and territories don’t observe daylight-saving time and thus won’t have to worry about changing their clocks back. Those are Arizona, Hawaii, Puerto Rico, the Virgin Islands, American Samoa, Guam and the Northern Marianas.

Click here to see what time it is in different cities around the world.

Daylight Saving Time is four weeks longer since 2007 due to the passage of the Energy Policy Act in 2005.

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The Act extended Daylight Saving Time by four weeks from the second Sunday of March to the first Sunday of November.

Daylight Saving Time will return on March 14, 2011.

The time change gives most of us an “extra” hour of sleep this weekend.  WBZ News Radio’s Deb Lawler spoke with a sleep expert who has some tips on getting a better nights sleep.

 WBZ’s Deb Lawler speaks with Pete Bils.

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WBZ-TV’s Lisa Hughes has more