week-from-dateTime() function extracts the amount of weeks from a DateTime attribute so it can be used to compare to a value. Values range from 1 to 53 (which values belong to which week will depend on the database implementation).
This query returns all the logs where the amount of weeks in
DateAttribute is “2” (for example, “2011-01-13”):
//Logging.Log[week-from-dateTime(DateAttribute) = 2]