PRB: Unexpected Date Value Returned from Format Function

The information in this article applies to:

- Microsoft Visual Basic programming system for Windows version 3.0

SYMPTOMS

When using the Date, Time, or Format function to return information about a Date/Time variable, you may get results other than what you expected. For Example, the following prints January:

   Print Format$(4, "MMMM") ' Print the Month represented by number 4

CAUSE

The value 4 when interpreted as a date is Jan 3, 1900. Dates are stored in Variants of VarType 7 (Date) as double-precision numbers. This number represents a date from January 1, 100 through December 31, 9999 -- where January 1, 1900 is 2. Negative numbers represent dates prior to December 30, 1899.

WORKAROUND

To get the string "April" to print when the only date information available is the Month 4, use a function such as DateSerial and supply it with an arbitrary Day and Year.

Step-by-Step Example

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a command button (Command1) to the form.

3. Add the following code to the Command1_Click event:

      Sub Command1_Click ()
   
         Dim AnyDay As Integer
         Dim AnyYear As Integer
   
         AnyDay = 1      ' Allowed values are: 1 to 31
         AnyYear = 1994  ' Allowed values are: 100 to 9999
   
         Print Format$(DateSerial(AnyYear, 4, AnyDay), "MMMM")
   
      End Sub
   
   

4. Run the program.

STATUS

This behavior is by design.