FileMaker Pro Custom Functions

Let([ StartTS = JobStartTimestamp; EndTS = JobEndTimestamp; StartD = GetAsDate(JobStartTimestamp); EndD =GetAsDate(JobEndTimestamp); StartT = GetAsTime(JobStartTimestamp); EndT = GetAsTime(JobEndTimestamp); LastJobDay = If(StartD = EndD;1;0); WorkSTime = WorkStartTime; WorkETime = WorkEndTime ]; /* Make sure no empty parameters */ If( StartTS = "" or EndTS = "" or WorkSTime = "" or WorkETime = ""; 0 ; /* No reverse allowed! StartDate has to be bigger than EndDate */ If( StartTS > EndTS or WorkSTime > WorkETime ; 0 ; /* We put the whole calc in another "Let" so we can create a number instead of time. See at the end. */ Let([ calc = /* Core Calc */ Case( /* Filter Weekends */ DayOfWeek (StartD) = 1 or DayOfWeek (StartD) = 7 ; 0; /* Filter Holidays */ FilterValues(StartD;HolidayList)>0 ; 0; /* If JobStartTime is later than WorkStartTime and its the last JobDay then Calculate JobEndTime - JobStartTime */ StartT > WorkSTime and LastJobDay = 1 ; If(EndT > WorkETime;WorkETime;EndT) - StartT; /* If JobStartTime is later than WorkStartTime and its NOT the last JobDay then Calculate JobStartTime - WorkEndTime */ StartT > WorkSTime and LastJobDay = 0 ; WorkETime - If(StartT > WorkETime;WorkETime;StartT); /* If JobStartTime is equal or earlier than WorkStartTime and its the last JobDay then Calculate JobEndTime - WorkStartTime */ StartT ≤ WorkSTime and LastJobDay = 1 ; If(EndT > WorkSTime; If(EndT < WorkETime;EndT;WorkETime) - If(StartT < WorkSTime;WorkSTime;StartT)); /* If JobStartTime is equal or earlier than WorkStartTime and its NOT the last JobDay then Calculate WorkEndTime - WorkStartTime */ StartT ≤ WorkSTime and LastJobDay = 0 ; WorkETime - WorkSTime; 0) ]; /* Change the whole Calculation to Decimal Time, so 1:00:00 becomes 1 in a number */ Round(Hour(calc) + (((Minute(calc) * 100) / 60) / 100); 2) ) /* Add the Hours recursive */ + /* Then run this until LastJobDay = 1 */ Case(LastJobDay = 0;ResourceHours(Timestamp(StartD + 1;WorkSTime);EndTS;WorkSTime;WorkETime;HolidayList)) )))
 Then copy & paste into FileMaker Advanced's Edit Custom Function window.