If you plan on writing a poem for the love of your life, do not wait for the Valentine's Day. Go right ahead, and do that. Time should not define as to when you should make the other person feel special. You are supposed to write one yourself.
You can copy it from some other place. It will still mean a lot to your partner.As far as the time is concerned, you can send them a piece of romantic poetry on the date you first met that is your first romantic date. Your lover will be astounded by the fact that you remember the date.
Source: http://www.endless-feeling.org