Time Stamps

The formula is brutal, but here is a gift.  it will be a formula numeric field type.

The formula uses fields called [Status Start] and [Status End] which are date/time field types. 



var timeofday DayStartTime = ToTimeOfDay("8:30 am");
var timeofday DayEndTime = ToTimeOfDay("5:00 pm");

var DateTime StartDateTime = Max([Status Start], ToTimestamp(ToDate([Status Start]), $DayStartTime));
 
var DateTime EndDateTimeTesting = If(IsNull([Status End]), Now() ,[Status End]);

var DateTime EndDateTime = Min($EndDateTimeTesting, ToTimestamp(ToDate($EndDateTimeTesting), $DayEndTime));

var Number WeekDayDays = WeekdaySub(ToDate($EndDateTime), ToDate($StartDateTime)) + 1; //(we count each day as a full workday) 

var number HoursBeforeStartEndAdjustment  = $WeekDayDays * ToHours($DayEndTime - $DayStartTime);

var datetime StartDateTimeBounded = 
  If(ToTimeOfDay($StartDateTime) < $DayStartTime, ToTimestamp(ToDate($StartDateTime), $DayStartTime), $StartDateTime);

var datetime EndDateTimeBounded = 
If(ToTimeOfDay($EndDateTime) > $DayEndTime, ToTimestamp(ToDate($EndDateTime), $DayEndTime), $EndDateTime);

Max(0,
Round($HoursBeforeStartEndAdjustment 
- Max(0,ToHours(ToTimeOfDay($StartDateTimeBounded) - $DayStartTime)) 
- Max(0,ToHours($DayEndTime - ToTimeOfDay($EndDateTimeBounded))),0.1))