For many years SAS did not have a format called WEEK. Customers often created user-defined formats with PROC FORMAT and used the format name of WEEK.

Beginning in SAS 9.1, a SAS WEEKw. format and informat were implemented but mistakenly not documented. If a customer had created a user-defined format called WEEK and attempted to use it in a program, SAS used its format called WEEK rather than the user-defined format by the same name.

Because the WEEK format and informat weren't documented, the decision was made to remove them from the software beginning in SAS 9.2. This decision allows legacy code, that includes a user-defined format called WEEK, to run as expected. Now, when customers create their own format called WEEK, they will use it when they reference the WEEK format in code.

A sample of how to create a format to produce the week number from a SAS date is in the Full Code tab.

Operating System and Release Information

Product Family	Product	System	SAS Release
			Reported	Fixed*
SAS System	Base SAS	OpenVMS on HP Integrity	9.2 TS1M0
		Linux	9.2 TS1M0
		Linux for x64	9.2 TS1M0
		HP-UX IPF	9.2 TS1M0
		64-bit Enabled Solaris	9.2 TS1M0
		64-bit Enabled HP-UX	9.2 TS1M0
		64-bit Enabled AIX	9.2 TS1M0
		Windows Vista	9.2 TS1M0
		Microsoft Windows XP Professional	9.2 TS1M0
		Microsoft Windows Server 2003 Standard Edition	9.2 TS1M0
		Microsoft Windows Server 2003 Enterprise Edition	9.2 TS1M0
		Microsoft Windows Server 2003 Datacenter Edition	9.2 TS1M0
		Microsoft® Windows® for x64	9.2 TS1M0
		Microsoft Windows XP 64-bit Edition	9.2 TS1M0
		Microsoft Windows Server 2003 Enterprise 64-bit Edition	9.2 TS1M0
		Microsoft Windows Server 2003 Datacenter 64-bit Edition	9.2 TS1M0
		Microsoft® Windows® for 64-Bit Itanium-based Systems	9.2 TS1M0
		z/OS	9.2 TS1M0
		Solaris for x64	9.2 TS1M0

* For software releases that are not yet generally available, the Fixed Release is the software release in which the problem is planned to be fixed.

If you simply want to produce the week number for a SAS date, here is some sample code.

---

/* PROC FORMAT with the PICTURE statement creates a custom format. The 
   %U directive writes the week number of the year (Sunday as the first day
   of the week) with no leading zero.

Today's date is written out using the WEEK format */

proc format;
  picture week 
  low-high='%U'(Datatype=Date);
run;

data a;
  x=today();
  put x week.;
run;

/* The SAS log displays the week value */

Type:	Usage Note
Priority:
Topic:	SAS Reference ==> Statements ==> Information ==> FORMAT SAS Reference ==> Statements ==> Information ==> INFORMAT

Date Modified:	2010-11-12 11:29:47
Date Created:	2009-02-27 13:09:06