The movement to "lock the clock" is growing as more research indicates that the biannual ritual of changing the time is not only annoying to some but harmful to public health, productivity and safety. This year, about half of states have considered or are considering time-related bills. Bills to abolish daylight saving time have been introduced for years, and have always faced opposition, including from sport and retail industries that say the extra hour of evening sun in the summer brings them more business.