I don't think he has any "learning disabilities." (Although I definitely have problems learning by hearing so he draws me diagrams sometimes.)
Don't think of this as a "disability" per se but more as a preference, the preferred way of taking in data. If I can see things on a calendar or on a chart, I can recall that image. I don't do that with audio, or at least I don't practice it.
The timing is important for me too. I sometimes have a mental layout of what I want to do and when. Knowing priorities and deadlines helps me plan my day. Not knowing that puts me into a guessing game and creates all the problems that come with assumptions.
