I've got a problem with how to define half a standard action.  

The hold portal ritual takes 1 standard action to cast. This is so the player can use it in combat. Now this player wants to create a scroll of this ritual.  

The rules of scrolls state the following [page 299 phb1 4e]:

> 
> Time: Casting a ritual from a scroll takes half the time indicated in
>  a ritual’s description, since the creation of the scroll has primed
>  the magic.
> 
> 
> 

So, how should I interpret half a standard action??