The ET7000 Digital Astronmic Timer is a really really good timer. There is a lot more to it than might appear on the surface. Using it to control a simple lighting system is not using it to its full capabilities.
I used them as they were the only digital timer I could find that was rated to operate to -40 Deg Celcius. All of the cheapo digi-timers I could find used Ni-CAD batteries that would freeze in the winter and loose their charge and ability to hold a charge.
Thankfully things have changed some in the past few years and we now have decent Astro-timers available that use Ni-Mh cells and don't cost a fortune.