Legrand 944243 The normal mode for this timer will have a clock time and the colon between hours and minutes will be blinking. If there is no power a large ring will be blinking around the display.

The one I have had 'crashed' and this ring was not blinking but broken into many pieces. None of the 3 buttons would do anything. The timer runs on a capacitor in between times of no external power. This will need to be allowed to discharge or forcefully discharged to reset this condition of unresponsiveness. To open the case, there are three holes along the back edge. A heavy wire that just fits the hole will dislodge the latch behind each of these holes. Keep pressure pulling the front out as you one-at-a-time use the wire to unlatch these. I used a 10 ohm resistor to discharge the capacitor inside, which took a few seconds.

The time will say 0:00 once reset. This may not mean the old programming is erased. Press the Right Arrow button. The Clock in the upper left and the Day (1~7) should blink. Press the + button to advance to the current Day of the week. Press the Right Arrow again and the Hour will blink. Press + to advance the hour to the current time. It uses 24 hour format. Press Right Arrow again and Minute will blink. Advance the minutes with +.

Pressing Right Arrow again will advance into the Programming mode and 'Pr' will show at the bottom-right of the display. The Day indicator will start on '1'. If the time blinks, there is no programming for this day. Pressing the Right Arrow will advance to the next day of the week. If a day does have a programmed start/stop, the time will remain solid and the outer ring will have black tick-marks during the 'on' time. These can be cleared by pressing the + and 'O' button at the same time. After advancing past the 7th day using the Right Arrow, the Pr will disappear and the time with the blinking colon will appear. This is the normal mode.

To Program a start/stop event, press the Right Arrow until the desired Day number is displayed along with Pr at the bottom right. Now press and hold the + until the desired start time is displayed (it moves up in 15 minute increments). Press the 'O' button. The display will have an icon in the upper right which will change to a half-solid oval. Advance to the desired Stop time by pressing the +. Press the 'O' button again to set the stop. This Icon will go hollow. The outer ring will have the tick-marks darkened for this 'On' time. Press the right arrow again to advance to the next day and repeat for more start/stop times.

I think my unit copied the programing from the previous day to the next. To erase the programming for a day, during programming, press the + and 'O' together.

You can check the programming by repeatedly pressing the right arrow, advancing through the day and time set, and then the programming days. Days with the programming will have the outer ring with the darkened tick-marks for the ON times (24 hours for the full circle). If there is no programming for that day, the time will blink.

When back in the 'normal' mode, the 'O' button can be pressed to alternate between Manual-On and Automatic mode. The clock disappears and a hand (I think it's a hand) appears in Manual Mode. In this mode, I doubt a Stop Time in programming will have an effect.

Good Luck! I fiddled with this timer for a while until I settled with this home-brew procedure. I hope it works for you. I couldn't find any documentation on the internet.

Harry