Bill at work told me about a timer switch he installed at his neighbor’s house. Purchased at Lowe’s, the timer has a microchip that allows you to enter the time and date and the time the sun sets that day. From then on the timer will calculate sunset and turn on the light at the correct time each day. You can also program the switch to turn off at sunrise or at a certain time in the middle of the night (or put it on a 7-day timer with several on/off cycles). I have four indoor lights on timer that I adjust a few times each year as the length of the day changes. A switch like this could eliminate those adjustments. I did a search and found another brand where you actually enter your latitude and longitude so that it can calculate sunset, but entering the current time and sunset also gives you a point on the curve that can be used. I believe the one he installed was an Intermatic EJ500C. They call this an “astronomic” timer. I will check to see if I can get it locally, but found a couple of places online to buy as well:
1000bulbs.com $18.34 free shipping
This device fits in a switch plate so that it could control the outdoor lamp which is on that switch and there is also a battery inside so that it won’t forget the time and date when the power goes off. They also make a plug-in version that I could use with my indoor lamps. These also have a “random” feature that will turn the lights on and off randomly to make it look like someone is home turning the lights on and off. But since my lights are on timer all the time my house always looks like nobody is home.
The downside, I realized later, is that these timers are not supposed to be used with compact fluorescent bulbs and all of the lights I want to control are CF bulbs.