Hi so I'm an intermediate level excel user and I have to calculate double over time >>>

The formula I have right now is to calculate over time after 8 hours

D1 is starting time and E1 is ending time (24 hour clock)

=IF((E1-D1+(E1<D1))*24>8, (E1-D1+(E1<D1))*24-8,0)

I have to make this DOUBLE over time, and I'm having a lot of trouble...

Any suggestions?