You can renew a domain name almost any time, and you can extend the expiration date up to 10 years from today.
Avoid letting your domain expire! The registry allows a short period of time to renew at your normal registration price, but then they raise the price considerably, and if you don’t pay the grace period redemption price they delete the name. Once the name enters the deletion queue, we lose the ability to retrieve it for you. You have to compete for it on its deletion date, and if you’re able to regain it, it may be expensive. We strongly recommend renewing your domains well in advance of their expiration dates to avoid the frustration and expense of this process.