I wrote a code to calculate work hours excluding Friday and Saturday and out of work hours
note that work hours is from 8:30 to 16:30
but it fails to calculate the work hours if the start Day is thursday as it shows at the picture marked in red

this is the code

Function CountWorkHours(start_date As Date, end_date As Date, holidays As Range) As Double
    Dim totalHours As Double
    Dim currentDate As Date
    Dim workStart As Date
    Dim workEnd As Date
    Dim isHoliday As Boolean
    Dim holiday As Variant
    Dim startHour As Date
    Dim endHour As Date

    ' Define working hours
    workStart = TimeValue("08:00:00")
    workEnd = TimeValue("16:00:00")

    totalHours = 0
    currentDate = Int(start_date) ' Start from the date part only

    ' Iterate through each date from start_date to end_date
    Do While currentDate <= Int(end_date)
        isHoliday = False
        For Each holiday In holidays
            If currentDate = Int(holiday) Then
                isHoliday = True
                Exit For
            End If
        Next holiday
       
        ' Check if current date is a business day (Sunday to Thursday) and not a holiday
        If Weekday(currentDate, vbSunday) <= 4 And Not isHoliday Then
            ' Determine the start and end times for the current day
            If currentDate = Int(start_date) Then
                startHour = TimeValue(start_date)
                If startHour < workStart Then startHour = workStart
            Else
                startHour = workStart
            End If

            If currentDate = Int(end_date) Then
                endHour = TimeValue(end_date)
                If endHour > workEnd Then endHour = workEnd
            Else
                endHour = workEnd
            End If

            ' Calculate the working hours for the current day
            If endHour > startHour Then
                totalHours = totalHours + (endHour - startHour) * 24
            End If
        End If
        currentDate = currentDate + 1
    Loop

    CountWorkHours = totalHours
End Function

please help and thank you