Ok Bradley, there it is:
=If(Floor(END)=Floor(START), Interval(END-START), //For task finished in the same day
// If not finished in the same day
Interval(17/24 - Time('$(=Time(START))') // Hours to finish the first day
+ Time('$(=Time(END))') - 8/24 // Hours from start of end day to due time
+ ((Floor(END)- Floor(START)-1)*9/24) //Complete days between
)
)
Hope his works, I didn't tested well.
