Hey i;m hector : MY PROBLEM / 7 DAYS SETUP NO WORK ; ( ej: TIME ON 8.00PM- TIME OFF 5.00AM( SEME DAYS MONDAY TO SUNDAYS?

Hi Hector.
You posted under ET171C8.
You have the timer in front of you, and whole manual cannot be repeated. So there are two options
1) Free option: Add a comment and say specifically where the programming is tricky. If you don't understand the buttons, or if display doesn't show, or if you can't find all days by pushing day button, or if you can't find the am pm choice.
2) Pay for fixya expert to walk you through each step via e-mail.

http://www.intermatic.com/~/media/files/intermatic/products/instructions/timers/et171c%20-%20english.ashx
http://www.intermatic.com/products/timers/electronic%20time%20switches/7%20day%2030%20amp.aspx

If display shows, then battery is correctly installed.

Instructions copied from manual:
1) RESET TIME SWITCH: Press the recessed RESET switch to reset the
microprocessor and delete any set point information which has been
programmed. NOTE: DO NOT press RESET after programming has
begun or you will lose all of your program information.
2) TO SET TIME AND DAY OF WEEK: Place the three position selector
in PROGRAM and the two position selector in CLK mode. Press the
HOUR, MINUTE and DAY buttons individually to select the current time
of day (12 hour AM/PM repeating) and the day of the week. Day 1 is
Sunday, day 2 is Monday, etc.
3) TO PROGRAM SET POINTS: Select PROGRAM mode with the three
position selector and OUTPUT mode with the two position selector.
Press the HOUR and MINUTE buttons separately to program the first set point time desired.
Press the DAY button to select the day the event is to occur.
Press the ON/OFF button to select an ON or OFF set point.
Press the ENTER button to enter that set point for the selected day.
Note that the ON or OFF indicator stops flashing only after pressing ENTER. If this set point is to occur for other days of the week, simply press the DAY button to select the next day then ENTER. Repeat for any additional days. Note that this allows you to utilize one set point for
any or all days of the week.
Then set timer to AUTO for programs to operate