[imp] cache lifetime decision?

[Liam Hoekenga]

>> With the new release, I see that many (most?) of the caches default to
>> having a lifetime of 86400 seconds (24 hours).  What's the reasoning /
>> benefit to this?
>
> No real reason - 1 day/24 hours is just a nice round, easily
> understood timeframe I guess.

But.. if someone visits the page with 24 hours, the caches don't have  
to be built from scratch?

Liak