While some humans may still be feeling the effects of this week's switch to Daylight Saving Time, at least the time change doesn't trigger hair loss and an overwhelming desire to shout out your loved one's name. But to a penguin, the light cycle dictates the life cycle. Everything from breeding to molting is controlled by the photoperiod, or the length of daylight these birds are exposed to each day. Over the past year, the lighting schedule in the Tennessee Aquarium's penguin exhibit has been gradually changed. This tiny daily time change for the gentoos and macaronis may mean baby penguins appearing earlier than past years. "The new lighting schedule allows visitors a little more viewing time in the evenings," said senior aviculturist Amy Graves. "And that subtle change is telling their bodies that it’s time to breed a little bit earlier this year. So we're going to give the penguins their rocks on March 21st which is about two weeks earlier than previous years..."