Access 2013/VBA function to compute time

Need a function that will compute how much time (in hours) is within certain time range (normal business hours, after-hours, or weekend) ..somewhat psuedo-code below.. TimeSplit(shift as char, date as date, timestart as time, length as number) split is either d - working hours a - evening/early am w - weekend demarc between working hours and after-hours should be changeable in function if date is on weekend then all the time is considered weekend time examples: (assuming working hours 9 am - 6 pm TimeSplit("w","10/25/2015","10:30 am", .5) = .5 TimeSplit("d","10/25/2015","10:30 am", .5) = 0 TimeSplit("a","10/25/2015","10:30 am", .5) = 0 TimeSplit("w","10/26/2015","10:30 am", .5) = 0 TimeSplit("d","10/25/2015","10:30 am", .5) = .5 TimeSplit("a","10/25/2015","10:30 am", .5) = 0 TimeSplit("w","10/26/2015","5:30 pm", 1.5) = 0 TimeSplit("d","10/26/2015","5:30 pm", 1.5) = .5 TimeSplit("a","10/26/2015","5:30 pm", 1.5) = 1 time will never span over a day