Get date using InputBox in VBA macro gives "Run-time error '6' - Overflow"

[LandyA]

I am trying to read in a start date for a macro in Office 365 Excel for Mac v 16.41 on OS X 10.15.7 and am getting an message "Run-time error '6' - Overflow" after clicking OK in the InputBox.  The macro has worked fine the past couple of years, but now returns this error.  I have not run it for a couple of months, so something in an Excel or OS X update must have changed behavior.  Here are a few lines that are enough to demonstrate the error.

Sub GetDateFromDialog()

  Dim StartDate As Date

  StartDate = InputBox("What is the Start Date?", "Start Date")

  ActiveSheet.Range("B3").Value = StartDate

end sub

It fails with the error before reaching the ActiveSheet.Range() command.

How do I get this working again?

[#2]

@LandyA 

Try

StartDate = CDate(InputBox("What is the Start Date?", "Start Date"))

or

StartDate = DateValue(InputBox("What is the Start Date?", "Start Date"))

[#3]

@Hans Vogelaar 

The version with DateValue() worked.  Not sure what has changed, but you got my macros working again.  Thanks for the help.

-LandyA