Say cell **A3 ='12:00 PM'** and **B3 ='6:00 PM'**

This formula will return **'6'**, for **6 hours worked**.

```
=IF(ISERROR((TIMEVALUE(B3)-TIMEVALUE(A3))*24),"0",(TIMEVALUE(B3)-TIMEVALUE(A3))*24)

```

However, I want the formula to **subtract breaks** for working a certain rage of hours. 
Say for example:

* > 
> 4.5 hours = No change
> 
> 
>
* > 
> between 5-7 hours = subtract .5 hour (30 mins)
> 
> 
>
* > 
> 7+ hours = Subtract 1 hour
> 
> 
>

What could I add to the code above to achieve this?