The Utilitec 0192773 timer has astro dusk-to-dawn functions.
The manual is very unclear at the exact point you need it to say how to set dusk-to-dawn.
The following page has the manual, with explanation how to find the astro dawn-to-dusk setting
http://waterheatertimer.org/Program-wire-Utilitec-0192773.htmlWhen you are programming the timer, press TIME button and hours start flashing.
Press the +/- button ... the trick is to keep pushing the +/- button until it finally gets to astro, and the sun-moon symbol shows on display.
When the sun-moon symbol shows, the display also shows AM.
Press the +/- again and PM show.
So if you want Program1 to turn lights ON at dusk (PM), then your display needs to show: 1 ON PM sun-moon.
To continue setting astro, do not set hours, just press PROG button.
Then repeat the steps above until: 1 OFF AM sun-moon show on display.