You haven't given us many facts upon which to base our advice. The right time is different for each couple and each individual. Without any facts other than 6 months, I can give some general observations.
The right time for you depends on your comfort level, your reason for telling your partner. Suppose you tell your partner and he does not say the same thing to you. How will you feel then? Will that make your relationship uncomfortable? Are you bursting with love and can't wait to say it?
How will your partner feel when he hears that? Will he treat it as a wonderful gift? Will he be afraid that those words carry come additional obligations on his part or that you have an agenda? How will he feel if he is not ready to say those words to you?
One additional note: whenever you do tell him, do it at a time when you are both fully clothed and not starting to get intimate. You don't want there to be any confusion between love and lust.
I would say when you love them lol. Really though, it's not really possible to say when it's the right time. Every relationship/person is different and without knowing all the ins and outs of the relationship it's impossible to say.
After a year. . I've seen this too many times on reality TV. It's a deep powerful phrase and you need to know what it really means before you say it. You need to wait, because the moment you say it, your heart suddenly becomes an open door, and it becomes fragilefragile and weak. Actions speak louder than words. Once you have experienced powerfully true loyal loving actions that have truly proven to yourself that you love this person, that this person is your future and your are their future, that you will sacrifice anything for... then say it. Because there's a huge difference between "I love you" And "I love having you" I love you means Self sacrifice, long suffering, slow temper, love, faith, etc Thereas "I love having you" could mean that you like a lot about the person. You're loving not being single, but that's not enough. You need to experience the pains and pleasures of who you love before you can admit you love them. But you need to be sure, that you are a person who is also just as much worthy of being loved and having the person tell you they love you.
You should say it if you feel fairly confident that he'll say it back. Or you could say it but be prepared for him to not say it back. Even if he doesn't, doesn't mean he never will. If you truly feel it in your heart, there is nothing wrong with expressing it. Communication is most important when it comes to relationships.
The right time is whenever you're sure! I was the first to say it to a former boyfriend and I did not expect him to say it back (primarily because he was going through a difficult time). It wasn't uncomfortable and I didn't dwell on it. Months later, he told me that he loved me.
Saying I love you is not about receiving a reaction. You are simply sharing a feeling. Likewise, I once had a boyfriend that said he loved me when he was unsure. It hurt me deeply when he eventually said that he "thought" he did. Saying I love you can be really wonderful. You just need to be sure that you truly feel this way about him and don't dwell too much on his reaction. If he isn't ready to say it back yet, it doesn't mean that he never will be. If that is the case, be patient and understanding. Show him that you do not expect anything of him and that just wanted to share that feeling with him :)