It’s a bittersweet time of year. On Saturday night before you go to bed, turn your clocks ahead one hour. The switch to Daylight Savings Time signals the start of spring, but also means you lose an hour of sleep. That has been blamed for an increase in car accidents and a jump in heart attacks and strokes the week after springing forward. Experts say to prevent being sleepy and less aware on Monday, go to bed an hour earlier Sunday night. And fire department officials remind you this is the time you should change the batteries in your smoke detectors.