WeekOfYeardate - any calendar dateFileMaker Pro 6.0 or earlierFractions of weeks occurring at the beginning or end of the year count as full weeks, so the WeekOfYear function returns values 1 through 54.Important To avoid errors when using dates, always use four-digit years. For more information about how FileMaker Pro handles two-digit dates, see Conversion of dates with two-digit years.WeekOfYear(“1/1/2014”) returns 1.WeekOfYear(ProjectDue) returns 6, when ProjectDue is 2/2/2014.WeekOfYear(“1/1/2014”) - WeekOfYear(“2/2/2014”) returns -5.