Ticket Due Date - not email generated - where to set the default?

I have reached my 1 hour search limit, so I am asking.
It appears I missed it during our implementation.  Our tickets all seem to be defaulting to a due date of 1 day.  
I have searched here and seen several references to the ability to change this default, but no direction on how or where.
 

Will someone show me or walk me thru where to find this setting?

Thanks,

Sollie