How to use Workday function using vba?

Try this:

Sub Docdates()
Dim ws1 As Worksheet
Dim ws2 As Worksheet
Dim HolidayRange As Range
Dim dtMyDate As Date

Set ws1 = Sheets("Data")
Set ws2 = Sheets("Actual")
Set HolidayRange = Worksheets("Sheet1").Range("D12:D16")

dtMyDate = WorksheetFunction.WorkDay(ws1.Range("B8") - 1, 4, HolidayRange)

ws2.Range("D1").Value = "Please send the file on " _
                        & Format(dtMyDate, "mm/dd/yyyy")

End Sub

The VBA code needs to be in a general module...not a sheet module
• ALT+F11...to open the VBA editor
• Select your workbook from the project window
• Insert.Module...to create a General Module
• Cut the code from the "Actual" code module and paste it into the new module

Last: Right-click on your button and assign the autotext macro to it.

Does that help?

OK...Define "not working".
When I follow the instructions I posted and click the button, the correct date is entered in the correct cell.