Instructions for setting 28457

See this sticky thread at the top of this forum.
https://www.askmehelpdesk.com/electrical-lighting/timer-manuals-mother-all-collections-timer-manuals-616475.html

Here is link to Westinghouse manuals:
Woods-timers-and-manuals (http://waterheatertimer.org/Woods-timers-and-manuals.html#outdoor)
Index of /pdf (http://waterheatertimer.org/pdf/)

The 28457 is dawn-dusk timer... but product numbers and designs change rapidly... copy following link and check if that matches your timer:
http://waterheatertimer.org/pdf/Westinghouse-28457_TimerManual.pdf