There lies so many old sources which indicates that Google “may” award higher rankings to old domains, but still there are many suspects that any ranking boost will be very small if it still exists at all. There are many factors here that could muddy the waters. Firstly, having an odd domain may have more links and authority which could leads to more number of pages and thus leads to higher rankings.
However, the question mainly lies whether an old domain could be awarded as higher Google Rankings simply because it is an old domain is difficult to ascertain. Individuals who attempt search engines often use “doorway” or throwaway attempt to obtain as much traffic as possible before being caught.
Google is clearly looking at data that may suggest the domain age, contact information changes may be monitored to filter out bad domains. The domain name server (DNS) record for a domain may be monitored to predict whether a domain is legitimate. It contains details of administrative and technical addresses, registered the domain, and the addresses of name servers. Thus, by analyzing the data over time for a domain, illegitimate domains may be identified.
As per the implementation, the date which contains a domain is registered may be used as an indication of the inception date of the document. Furthermore, it is clear that the techniques which is used to determine the spammy domains that do not work in isolation, and that several negative factors may be required before a domain is marked as spammy.
As per the matt cuts, there is no need to worry about that much, as there lies not a big difference between a six-month domain and a one-year domain. In addition, he stressed to focus on the quality of the backlinking and content when it comes to ranking. According to him, yes, it might takes some time or there may be delay in few months before getting rankings but yes, there is nothing to worry about.
Buying an old domain or the domain having age act as a signal that the domain is not spammy or using any black hat practices. Age is just a correlation, not a causal link. Matt Cutts, says that Domain Age is just a small factor for ranking, no Google Trends Analyst has spoken out on the issue rebutting this since.