BUG: DateSerial Does Not Give Error for Invalid Month or Day

The information in this article applies to:

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, versions 2.0 and 3.0

SYMPTOMS

The DateSerial function doesn't generate an error when you use values for the month and the day arguments that are outside the ranges specified in the "Microsoft Visual Basic: Language Reference" version 1.0 manual.

You can use a numeric expression for each argument representing the number of days, months, or years before or after a certain date. But you will get an "Illegal function call" error message if you use a value for the year that is not between 1753 and 2078 (inclusive). You also get the error if the date specified by the three arguments either directly or indirectly evaluates to a date that is before January 1, 1753 or after December 31, 2078.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Page 65 of the "Microsoft Visual Basic: Language Reference" version 1.0 manual states the following:

"...the range of numbers for each DateSerial argument should conform to the accepted range of values for the unit. These values are 1 to 31 for days, and 1 through 12 for months. You can also specify relative dates for each argument by using numeric expressions representing the number of days, months, or years before or after a certain date...."

You can actually have values outside these ranges for the month and day argument and Visual Basic will not give an error. For example, a value of 0 for the day evaluates to the last day of the previous month. A value of 13 for the month translates to the first month (January) of the next year.

The following are examples of statements that will not produce errors:

   x# = DateSerial(63,7,12)    'evaluates to July 12, 1963
   x# = DateSerial(63,13,5)    'evaluates to January 5, 1964
   x# = DateSerial(63,7,33)    'evaluates to August 2, 1963
   x# = DateSerial(63,10,-1)   'evaluates to September 29, 1963
   x# = DateSerial(63,-1,5)    'evaluates to November 5, 1962

   x# = DateSerial(1750,3,1)   'evaluates to March 1, 1750
   x# = DateSerial(2078,12,40) 'evaluates to January 9, 2079
   x# = DateSerial(1753,-5,20) 'evaluates to July 20, 1752

Keywords          : buglist3.00 EnvtRun RefsDoc buglist1.00 buglist2.00 kbbuglist kbenv kbtlc
Version           : 1.0 2.0 3.0
Platform          : WINDOWS
Issue type        : kbbug