WEEK( )
Returns a number from 1 to 52 representing the week of the year.
Syntax
WEEK(date)
Argument
date
The date or date expression whose week of the year to get.
Returns
A number representing the week of the year for the specified date value.
Example
The following example gets the week number of the year for each date value in the ShipDate data field:
WEEK([ShipDate])