4 wire bathroom timer

[clockmaker]

I'm installing a timer for the bathroom fan. It seems that there is only a 12-2 coming into the switch box. The timer has a black, blue, white and green. I tied the switch black to the black and the switch blue to the white then the switch ground and the switch white to the ground. I suppose it is ok everything works as it should. Does anyone see a problem with this setup?

I wired up another timer but that switch box had 2 ...12-2 wires in it. One coming in from the power and then the other running up to the fan. I tied the switch black to the hot black the switch blue to the black going up to the fan then the whites together and the grounds together. This setup seemed to be the way to go. Not sure about the previous set up.

Thanks George