Date and Time calculation - breaks excluded

Hello all,

I am truly having a moment and struggling with this.

I have a date/time in this format: 31/01/2017 09:00 in C5 and trying to get a desired finish date in the same format in C6.

This is based on the number of hours to complete the task in a number format in F5. However I want to take in account weekends, breaks and meetings in order to get an accurate completion time and date. A28-C33 contains the below:

08:00 Start
08:00 08:15 Meeting
10:00 10:15 Morning Break
12:45 13:15 Lunch
16:15 16:30 Meeting
16:30 Finish

Basically Monday-Friday start at 08:15 and finish 16:15 with a 15min break at 10am and 30min lunch at 12:45.

For example
C5-30/01/2017 14:00 F5-4 Therefore C6 should be 31/01/2017 10:00

Any assistance would be greatly appreciated, my mind is getting mixed up.

Peter

if start is at 0815 then 1st and 2nd meetings are not included, are they?

unfortunetly, solution with worksheet functions is beyong my posibilities
in the attached file there is a user defined function dttm

@tim201110 The start time can vary from 7am to 8am therefore the first meeting would be taken in account if a 7am start. I didn't include that as it is an added complexity in the situation.

@avk I removed the data in F5 but for example f9 has a value of 5 hours to complete that task. Therefore the time added is to cell C9 to create D9 negative breaks and lunch.

@tim201110 I honestly dont know how you have managed that but that does give it as a calculated function I can put in the figures and it gives the answer that is required. I am impressed. How would this work with a 7am start for example?

Thank you for your assistance.

@tim201110 That is brilliant, can I be a pain and ask for a 7:00 start. So would be
07:00-08:00
08:15-10:00
10:15-12:45
13:15-16:15

Thank you again so much, that is absolutely brilliant.

@tim201110 Thank you for all your help that is exactly what is needed thank you.