Why do we need to sync clocks to the rising sun though? We can create an alarm clock that goes off at sunrise using the same smart technology. We don't need to

Why do we need to sync clocks to the rising sun though? We can create an alarm clock that goes off at sunrise using the same smart technology. We don't need to change the time metric. Now you might argue you need to do this because business demands that we start at 9am. Well THAT is what needs to change. Most jobs don't need a fixed start time. If they say come in between 7am and 10am that should give enough leeway so you can rise at sunrise. And in any case a 7am fixed sunrise and a 9am fixed work start time is still an issue for those who need > 2 hours to get ready for and commute to work.