Does the amount of time a domain has left before expiry help?

I've seen some people talking about age of domain or length of time left until a domain expires being important.

My domain is new so it won't rank for age, but if I renew it for another few years will this help? How long should a domain be registered for to give the Google spider confidence that my site is worth ranking?

 

They say the time to expire shouldn't be less than a year.

 

I always registrar my domains for 3+ years. The reason is that there are tons of spam sites on the net and scene they will probably get banned anyway they only registrar for one year. Plus your telling Google and the other search engines that your website won't be around long! So to them your website looks unimportant.