Function that returns next Friday from date - excel

Question

When planning projects we give a approximate duration in weeks. A project starts on the next Monday from today.
Public Function NextMonday() As Date
Dim D As Integer
Dim N As Date
D = Weekday(Now)
N = Now() + (9 - D)
NextMonday = N
End Function
With this code I can assign the right date to a cell (Next Monday). Now i need to get the next Friday 12 weeks from that date. (84 Days)
For this i used the previous code and adjusted it a little.
Public Function NextFriday(AproxDate As Date) As Date
Dim E As Integer
Dim M As Date
E = Weekday(Now)
M = AproxDate + (14 - E)
NextFriday = M
End Function
Now for the main module the code looks like;
Private Sub Worksheet_Activate()
Dim wbCurrent As Workbook
Dim wsCurrent As Worksheet
Dim StartDate As Range
Dim AproxDate As Date
Dim EndDate As Range
Set wbCurrent = ThisWorkbook
Set wsCurrent = wbCurrent.Sheets("Sheet1")
Set StartDate = wsCurrent.Range("C15")
Set EndDate = wsCurrent.Range("C16")
Call NextMonday
StartDate.Value = NextMonday
'Setting Monday 12 weeks from StartDate
AproxDate = NextMonday + 84
Call NextFriday(AproxDate)
EndDate.Value = NextFriday
End Sub
The NextMonday part works fine, but when running the NextFriday i get an "Argument Not Optional" When trying to set the EndDate.Value = NextFriday.
I cant seem to find the problem with this code. Any thoughts?

Answer 1

This is not how you get a value from a function:
Call NextFriday(AproxDate)
EndDate.Value = NextFriday
If you want the value that function NextFriday returns based on (AproxDate) and you want that value in cell EndDate then (instead of both lines above) you would use:
EndDate.Value = NextFriday(AproxDate)
You only use Call with a function if you do not want a value to be returned from it.
Simplified Procedures:
Your procedure are needlessly overcomplicated.
Believe it or not, this is exactly the same as your procedures:
Public Function NextMonday() As Date
NextMonday = Now() + (9 - Weekday(Now))
End Function
Public Function NextFriday(AproxDate As Date) As Date
NextFriday = AproxDate + (14 - Weekday(Now))
End Function
Private Sub Worksheet_Activate()
.Range("C15")= NextMonday
ThisWorkbook.Sheets("Sheet1").Range("C16")= NextFriday(NextMonday + 84)
End Sub
Simplified even further:
Going a step further, this is 1 sub is exactly the same as the 3 procedures above:
Private Sub Worksheet_Activate()
With Sheets("Sheet1")
.Range("C15") = Now() + (9 - Weekday(Now))
.Range("C16") = (.Range("C15") + 84) + (14 - Weekday(Now))
End With
End Sub
One more thing to note, function Now returns the current date+time. Id it's only the date you're interested in, use function Date.

Answer 2

You have 2 mistakes in your Next Friday function.
1) from Monday to Friday in Weekdays is +4 and not +5 (so you get Next Monday = +9 and next Friday = +(9+4) )
2) You took the now() instead of aproxdate in the next friday code
Your code for next friday should be:
Public Function NextFriday(AproxDate As Date) As Date
Dim E As Integer
Dim M As Date
E = Weekday(AproxDate)
M = AproxDate + (13 - E)
NextFriday = M
End Function
Then you can call the function as in the other answer

Answer 3

var d = new Date();
d.setDate(d.getDate() + (5+7 - d.getDay()) % 7);
document.write(d);
This is a Javascript code which will result you next friday, the only condition where it fails if it is a friday.