How far ahead can I prepare this coleslaw recipe?
That looks to me to be a lot of 'wet' to 'dry', so without really having a definitive answer I'd have 2 considerations.


How far you want your fresh garlic to 'mellow' [I really don't know the correct term for leaving crushed garlic so the sharpness goes off a bit.]  
How much water is going to be pulled from the apple.


1 could be affected by simply making up the dressing part early, then leaving it to mellow.
2 might be a bit trial &amp; error, but that's the one I can't think of a way round other than 'leave it out til late.' Better crunchy than soggy with a runny dressing. 

Carrot [&amp; most other things in regular coleslaw - cabbage, onion etc] I'd give one to three hours in the dressing before serving, but even that may come down to personal preference. The standard coleslaw I'm right now going off to make will be eaten in about 3 hours ;)