Custom column based on time value

Hi,

I've not worked with creating a custom formulae where time comparisions are used and was hoping for some pointers.

I have two columns:

1. AppointmentBookedTime: the time a user booked an appointment using our system. eg, 04/07/16 09:22:33
2. AppointmentTime: the time when the actual appointment is to take place (in the future) e.g. 05/08/ 11:30:00

I want to create a cusotm column called BookedTimeBusinessHours that returns a Y/N response for each row where:

• Y = if an appointment was booked between 9am and 5pm
• N = if an appointment was booked between 5pm and 9am

Any tips on the formulae requried to acheive this?