Calculating a timesheet for employee's

[Sammy21]

Hello,

I'm quite new to Excel and i was wondering if you could please help me.

My friend works really dodgy shift patterns and some involve working days and through the night, she asked me to create a spreadsheet that could calculate her overtime for her and ive been trying my best to do this but i keep getting stuck with the times going across midnight.

if anyone could help i would greatly appriciate it.

This is what i have so far