By Stephanie Stahl

PHILADELPHIA (CBS) — With the start of daylight saving time this past weekend, we lost an hour of sleep. Many are feeling the affects. How much sleep do we really need and can you catch up? Health Reporter Stephanie Stahl has the 3 On Your Side sleep test.

Turning the clocks ahead an hour has some feeling tired. Can the time change make you cranky and unfocused? Experts say yes, it’s true.

“They might find that they’re a bit more forgetful. They may not necessarily be able to focus or concentrate as much on their computers or other work,” said Dr. Karl Doghramgi, Director of Jefferson’s Sleep Center. 3 On Your Side asked him to clear up some misconceptions about sleep. “The best way to gauge how much sleep you need is really the way you feel during the day,” said Dr. Doghramgi.

While sleeping seven to eight hours a night is the average, some people can get as little as six hours without feeling deprived.

True or false, you can catch up on sleep.  It’s true.

“Most of us do that. We spend less time asleep during the week and then we catch up on the weekends,” said Dr. Doghramgi.

But some worry if you sleep a lot, you’re more likely to be overweight, that’s false.  Actually obesity is related to not sleeping enough.

“We do tend to gain weight because sleep deprivation changes our hormonal status,” said Dr. Doghramgi.

And having a drink, helps you relax, right?

Stahl asked Dr. Doghramgi, “A lot of people think that alcohol helps with sleep. Is that true or false?”

Dr. Doghramgi replied, “It’s actually false.”

While it might help initially, alcohol can cause more sleep disturbances during the night.

What about when you go to bed? Some say you can sleep any time, without impacting the quality of your rest. That’s false.

Just ask anyone who works at night.

“It is best to get that sleep when it’s dark outside because we know that the light does interfere with ones sleep quality,” said Dr. Doghramgi.

Whenever you sleep experts say to keep your room dark and cool and don’t use your electronics in bed.

National Sleep Foundation Healthy Sleep Tips