It works for me. I believe that you may be using a DD/MM/YYYY format.
Yes, the system settings are for dd/mm/yyyy, which is the correct short date format here (The date is given above as April 2, 2010 for 2/4/2010).
The example given in the documentation may be correct for users in the US and parts of Canada (or using US regional settings), but for others it is not.
Changing the example to, for example, 2/2/2010 would result in the answer being correct in most locales (although not for those that use yyyy/mm/dd).
Perhaps FMI should have a disclaimer in all the help sections that pertain to date that the examples are in MM/DD/YYYY format. I dont think that they will create dynamic help documents where the examples would change depending on how the date format has been setup for that file or system.
Thank you for your post.
I have forwarded the entire thread and screenshot link to the manager of our Documentation. I suggested adding the following information to the second example:
WeekOfYear (ProjectDue) returns 6, when Project Due is 2/4/2010 (using mm/dd/yyyy date format)