I'm finding myself incredibly excited about the DFRPG system!  I have a few questions related to Thaumaturgy that I'm hoping somebody can help me with. 

I've been thinking about a good luck spell that just adds a temporary aspect for a good long duration like maybe a couple hours or even a day.  What would the cost be to add that aspect to a willing person?  Would it be 1 plus the aspect cost of 0 (temporary aspect) plus the duration or would the base have to beat the target skill even if they are willing? 

Is there a general rule of thumb for duration?  is it fair for a base thaumaturgy spell to last an hour if there is an aspect involved? 

Thanks in advance!