I try to keep my sleep schedule so I wake up shortly after daybreak for exactly this reason. I love natural light and loath sleeping through it. I've considered writing an app that sets an alarm to sunset and a reminder 9 hours prior to sunset so I can always wake with the sun and have plenty of sleep. Should be pretty simple I just haven't gotten around to it. (Though personally, I'd prefer it were a personal choice…
Would buy for $4.99.