Net Work Duration (Working Hours)

If this works for you, I will update the Quick Measure:

mNetWorkDuration = 
// Get the start and end dates
VAR __dateStart = MAX([Date_Start])
VAR __dateEnd = MAX([Date_End])
// Calculate the Net Work Days between the start and end dates
VAR __NetWorkDays = COUNTX(FILTER(ADDCOLUMNS(CALENDAR(__dateStart,__dateEnd),"WeekDay",WEEKDAY([Date],2)),[WeekDay]<6),[Date])
// Set this to the start of the work day (7:30 AM)
VAR __startTime = TIME(7,30,0)
// Set this variable to the end of the work day (6:00 PM)
VAR __endTime = TIME(18,0,0)
// Calculate the duration of a full day, in this case in minutes
VAR __fullDayMinutes = DATEDIFF(__startTime,__endTime,MINUTE)
// Calculate teh number of full days, this accounts for the possibility that tickets start and end on the same day
VAR __fullDays = IF(__NetWorkDays < 2,0,__NetWorkDays-2)
// Calculate the total duration of all full days.
VAR __fullDaysDuration = __fullDays * __fullDayMinutes 
// Calculate the start time of the current record
VAR __startDayTime = TIME(HOUR(__dateStart),MINUTE(__dateStart),SECOND(__dateStart))
VAR __startDayTime1 = SWITCH(
                            TRUE(),
                            __startDayTime>__endTime,__endTime,
                            __startDayTime<__startTime && __startDayTime>TIME(0,0,0),__startTime,
                            __startDayTime
                        )
// Caclulate the duration of time for the first day
VAR __startDayDuration = DATEDIFF(__startDayTime1,__endTime,MINUTE)
// Calculate the end time of the current record
VAR __endDayTime = TIME(HOUR(__dateEnd),MINUTE(__dateEnd),SECOND(__dateEnd))
VAR __endDayTime1 = SWITCH(
                            TRUE(),
                            __endDayTime>__endTime,__endTime,
                            __startDayTime<__startTime && __startDayTime>TIME(0,0,0),__startTime,
                            __endDayTime
                        )
// Calculate the duration of time for the last day
VAR __endDayDuration = DATEDIFF(__startTime,__endDayTime1,MINUTE)
// The total duration is the duration of all full days plus the durations of time for the first and last days
RETURN  
IF(__NetWorkDays=1,DATEDIFF(__dateStart,__dateEnd,MINUTE),__fullDaysDuration + __startDayDuration + __endDayDuration)