Approximate

Let me set up a situation. Let's say I'm psychic, but not very good. My brother can predict the future much better than me.

So someone comes to me and I get this impression that they will be in a car accident. I can give them the approximate time it will happen, but that isn't good enough. They want to know the EXACT time so they know not to be driving then. So I refer them to my brother.

Would I inform them that he is capable of giving them a more approximate time, or a less approximate time?

In other words, does the usage of approximate focus on the inaccuracy of my guess in relation to an exact time, therefor a less approximate time would be more exact.

Or does the definition focus on the relative accuracy in spite of not being exact, and therefor a more approximate guess would be more exact.

I would settle on a third option, that "approximate" should not be used with comparative terms.

This sort of phrase comes up a lot in my work, and I always say "That time is only approximate, if you call back in a week I can give you a more approximate time." And then I pause and think my grammar sounded a little weird.

Thoughts?