Is there a difference between "convenient for you" and "convenient to you"? And if it is, could you explain it?
As well as the most common sense of convenient (i.e. suiting you, not causing you time or trouble), there is the related sense of close, near-by, as in "We stopped at a convenient gas-station" or "He picked up a convenient rock". While the phrase convenient for you is much the more common of the two, it could be that convenient to you is more likely to be used with this second sense.
Here are some examples from a quick search:
While Answer 1 is the correct choice when the word "convenient' is related to location, using the word to doesn't apply as absolutely when the meeting's time is under negotiation.
It works to say "convenient to you," when you're suggesting that a location can be reached with little effort, like "near to you" or "next to you." This ruling is reinforced by the impossibility of saying "near for you" or "next for you."
But if the matter of discussion is an activity where time is the dominant question it offers enhanced clarity to suggest that to someone that they join in at a time that is more "convenient for you," even though to is technically OK.