VBA Basics - Calling Function From a Sub

Question

I want to write a Function Macro that calculates the days between two dates. It looks like I have that.

Function daysRem(today As Date, eoc As Date) As Integer
    daysRem = Abs(DateDiff("d", today, eoc))
End Function

Now, I need to "Call" that function from a Sub to roughly estimate the number of weeks remaining. I'd like that to be in a message box. That's where I've hit about 2 hours of frustration. This has got to be simple, but I just can't figure out what to do.

Answer 1

Try this:

Private Sub DisplayDaysDiff()
 Dim dtDate1 as Date
 Dim dtDate2 as Date

 dtDate1 =ThisWorkbook.Worksheets("Sheet1").Range("A2")
 dtDate2=ThisWorkbook.Worksheets("Sheet1").Range("B2")

 MsgBox "Days difference: " & CStr(daysRem(dtDate1, dtDate2)), vbInformation

End Sub

Call it from a button_click event

Answer 2

Sub Main
    x = MyFunction(Param1)
End Sub

MyFunction(MyDate as Date)
    MyFunction = DateDiff("ww", Date(), MyDate)
End Function

You assign the value to the function name. The inbuilt Date() function is todays date.

Functions return something. Subs don't. Macros ARE SUBS.

Functions return something.

So

Function Test
    Test = 5
End Function

Sub Main
    x = Test() + 5
End Sub

So x = 10 .

Sub Main
    Param1 = #2/2/2017#  
    Range("B4").Value = MyFunction(Param1)
End Sub

MyFunction(MyDate as Date)
    MyFunction = DateDiff("ww", Date(), MyDate)
End Function

Date is both a data type and a function. One doesn't have brackets and one does.