How to set it to 12 hours on 12 hours off - Woods Industries 59377 Indoor Digital Timer 7-day

You posted under Woods 59377 timer.
Open following page to identify timer for sure:
http://waterheatertimer.org/Woods-timers-and-manuals.html#59377

Manual appears below
http://waterheatertimer.org/pdf/Woods-59377.pdf

1) When programming, you can set 8 programs with choices of different blocks of days.
In your case, you want 1 program (Prog1) for all days of the week: So when selecting days, you want MON, TUES, WED, THURS, FRI, SAT, SU to display

2) When programming, you first set Prog1 ON, and then select all days as shown above, then set hour for 12am, and then set minute for 00.

3) Secondly you set Prog2 OFF, and then select all days as shown above, then set hour for 12pm, and then set minute for 00.

4) If 12am and 12pm do not display for some reason, then set times for 11:59am and 11:59pm.

5) Programming steps:
-Press PROG button until 1 and ON display. This is Prog1 ON.
-Press DAY button to select days
-Press Hour button to set hour
-Press MIN button to set minute
-Prog1 ON is set

-Press PROG button until 1 and OFF display. This is Prog1 OFF.
-Press DAY button to select days
-Press Hour button to set hour
-Press MIN button to set minute
-Press PROG button to validate settings
-Prog1 OFF is set
-Press CLOCK button to return to current time

6) Manual shows other features

7) Add a comment for more free help.
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