How To Program an Astronomical Timer (Intermatic DT620)


Follow these steps to Program an Astronomical Timer (Intermatic DT620) for your next outdoor landscape lighting installation. Click Here to watch an instructional video on how to program the DT620 timer.

  1. Remove separator card from back battery compartment.
  2. Set current Time & Date. Whatever is blinking on the display is what you will be changing. Turn the dial till the correct hour is showing, press OK. Now the minutes will be blinking again turn the dial till the correct minutes are showing, press OK. Now you will set the current Date using the same steps, once you have the correct Day, press Ok and so forth.
  3. Now it will ask AUTO, this is for daylight savings. Select this and the clock will Automatically adjust for daylight savings, press OK.
  4. It will now show the week and day for daylight savings, if yours is different turn the dial and press OK to make the changes, if not then press OK till you come to the states.
  5. Turn the dial till the correct state abbreviation appears. Press OK.
  6. Now you will select which area of the state you live in, again turn the dial till the correct area appears, press OK.
  7. You will see TZ appear,  the blinking is your Time Zone, turn the dial till the correct Time Zone appears, press OK.
  8. The program will now show you the current times for Sunrise and Sunset, press OK for each.
  9. The screen should now display the current time with the current day below it, in the top left part of the screen you will see the word MAN, this is indicating that the clock will need to be turned ON and OFF manually, we will get to that next.
  10. We will now set the time for the clock to turn ON and OFF
    Push the word PROG, this will start the Programming mode. You will see a number 1 blinking, this indicates the ON event, push PROG.
  11. In the top left area you will see the word SKIP flashing, this would be selected if you wanted to skip this program. You need to select a time to turn ON. As you turn the dial, you will see different options. It is important that you select ON (not OFF) so now ON appears in the top left corner. Once you have selected the ON mode, press PROG and the days will be blinking in the bottom of the display. If you want every day then press PROG, if you want certain days then turn the dial till the days desired appear, then press PROG.
  12. Now the number 2 is flashing, this is the OFF event, again push PROG and go thru the same steps as ON but make sure the word OFF appears in the top left corner.
  13. Once you have gone thru all the steps and arrive at event 3 you can select another time to turn ON and OFF. Once you are happy with your time selections you can now press OK. This screen will show the current Time and Day, notice the word AUTO now appears in the top of the screen. You have set the timer to come ON and OFF Automatically.
  14. To check the ON and OFF times simply push the PROG button and then turn the dial, advancing thru the set events. Check to make sure the TIME, DAYS and ON or OFF are correct. If correct press OK and the clock is set. If not correct you can change the Programs by simply pressing the PROG button and repeating the procedure. To reset the time you will need to press the MODE button until you see the word CLOCK, press OK and go thru the initial set up again. You will need to go thru the whole set up again ending when you see the correct Time and Day. Push the PROG button, roll thru the settings, and if correct push the OK button. This will toggle the clock from MAN back to AUTO.
  15. If you need to reset the clock, press and hold the OK button while inserting a small round long object, like a paper clip, into the hole below the OK button and holding it till the screen goes blank.