[Orgmode] Active timestamp with notification in advance

[Wanrong Lin]

Hi,

Currently we can set the number of days a deadline should be notified in 
advance with something like this:

* TODO Do this
 DEADLINE: <2008-03-24 Mon -30d>

But it does not work on a plain active time stamp like this:

* TODO See Doctor
 <2008-03-24 Mon -30d>

Can we consider adding this feature to plain active time stamp? It would 
be great for appointment notification.

Thanks for giving that a thought.

Wanrong