The way I see there is only 1 option.
That is to invert the output if the 555. Then the relay will remain off and sw. on when time is set.
U need to add an additional transistor and a resistors to the PCB. It won't easy to solder if you never done SMD soldering in tight places
Or may be replace the SMD transistor with a PNP and some additional R's might do the trick.

Better yet use the Relay contacts to do what you want. Cause it has SPDT contacts you know.
N/O and N/C are there so why don't you use those.

I can solder, however trying to keep as simple as possible, so adding things to the board is more than I was looking for.. perhaps there is a correct item you could link to?

Using the relay contacts to achieve what I want... like having the relay interrupt the current to another relay , which switches on at power up... and off when 'interrupted'... I considered this, but then I would need a power supply to power the thing, and another to power the second relay... is this what you were talking about?

 

No..The relay has the set of contacts that are open at power up. Th N/C contacts.
Another 12V relay could also do what you need and it can use the same power you are supplying to the timer PCB

 

No..The relay has the set of contacts that are open at power up. Th N/C contacts.
Another 12V relay could also do what you need and it can use the same power you are supplying to the timer PCB

It doesn't seem that the N/C are open at power up...they are still closed before power up, and during the delay time... until the time expires then the N/O closes, and stays that way...
yes I suppose another 12v relay would have to do if theres no way to change this one... and theres no correct item out there to buy!

 

What you are looking for is known as a INTERVAL ON timer, you may find a cheap one on ebay, but there are definitely ones out there that are configurable by dip SW, but usually not at Chinese prices.
You could modify yours, unfortunately it is not as easy when SMT components are used.
Max.