How to set a Click 24/7 Digital Timer?

[Michael100]

I am experiencing difficulty setting a "Click 24/7 Digital Timer".  I want it to start 5:00 pm each day and off at 5:03 pm. 
It will turn on a pump attached to a water tank and deliver water right round our gardens front and back. I have had it operating for over ten years and it worked wonderfully well until the timer packed up. I have a new timer and cannot set it up correctly. I have taken it with the instructions back to my local Bunnings and requested assistance on three separate occasions. Each time I have taken it home it did not work. The last time was this morning and mid afternoon I discovered my garden well watered, no water in the tank and pump still running and two hours before it should start up.
I now know I should have set it up inside the house on a lamp instead of the pump.

Any suggestions would be most welcome.

  

[MitchellMc]

@OzRuss,

Could you please confirm that it is the current Click 24-Hour 7-Day Digital Timer that is not behaving as it should and not the older superseded model? That would help with our investigation.

Mitchell

[Michael100]

All of the three timers I bought were the old model CLKTS02 model. The last one was definitely the old model as I still have it and the receipt.

Michael