PRB: DateValue Argument Gives "Illegal Function Call" Error

You will correctly get an "Illegal function call" error for the DateValue argument if the short date (the three numbers representing the month, day, and year such as 4/24/92) does not follow the order of the date format selected under International settings in the Windows Control Panel.

This behavior is by design.

The DateValue function returns a serial number that represents the date of the string argument. The string argument can be a date in abbreviated form (three numbers that represent the month, day, and year). However, this has to conform to the Short Date Format selected in the International settings of the Control Panel.

By default, the order is MDY or the month followed by the day and then the year separated by a slash (/) or a hyphen (-). An example of a valid argument is 4/24/92 for the date April 24, 1992. Using 24/4/92 would produce an "Illegal function call" error.

NOTE: For the long form of the date, DateValue recognizes April 24, 1992, Apr 24, 1992, 24-Apr-1992, and 24 April 92".

Remember that you will have to restart Windows for any changes made in the International settings to take effect.