Door bell timer using 555 IC?

[Yorkie]

Thanks so much for your sound advice guys, and the time you've taken to make suggestions for amending the circuit.

I've now re-drawn the PCB layout to incorporate those suggestions, and have appended the circuit, artwork and component overlay.

I've added the 330 R resistor, zener and 47 uF cap across it, plus a smoothing cap as recommended. (I'd actually included one in the first layout, but had omitted it in this one).

I'm checking with my chum to find out whether the bell transformer is actually 12V AC rather than 8V (which many of them are).

I guess that if it's 8V AC, I'd be safe to omit the zener, the 47uF cap across it, and the 330R resistor?

How does that look  fellas?