Spain only requires the passport to be valid for the duration of the visit. However the airline or tour operator may require it to be valid for up to 3 month after the date of return. You will need to check with them.

If you intend travelling again you can renew it now and any unexpired period up to 9 months will be added.

luci

I think the theory is in case something happens and you need to stay out of this country longer. ie you become too ill to travel home or perhaps some weird industrial action or even a terrorist threat.

As per one of the previous posts if you get a new passport tomorrow it will expire ten years after the expiry date of your current one.

I'd get a new one personally.

I'd say get a new one done - mind the farce we've had trying to get 3 of ours done this year has not only driven me insane (stupid phto rules) but also the cost as well has been horrific!