Sunwait
Sunrise/sunset utility for Windows Task Scheduler or cron.
... - ie dusk range is 3:30pm to 10:30pm here, so it reasonable to schedule a dusk task at 3pm and allow Sunwait to pause the task for between 30mins and 7 and a half hours. If you scheduled the task for 6pm, then your lights will come on no earlier than 6pm.
The sun's position is calculated using time, and position - latitude and longitude should be specified on the command line.
This project is a fork from the work by Dan Risacher. The code also runs on Linux: download all files and run 'make'