Please explain about Weekdate format? like weekdate3.; weekdate9.; etc

[Thirumagal manivannan]

Hi, Please explain about Weekdate format?  like weekdate3.; weekdate9.; etc How do we calculate 3, 9,15 and 117? I have pasted weekdate format example from google.

Examples

The example table uses the input value of 16601 which is the SAS date value that corresponds to June 14, 2005.

SAS Statement	Results
	----+----1----+----2
put date weekdate3.;	Tue
put date weekdate9.;	Tuesday
put date weekdate15.;	Tue, Jun 14, 05
put date weekdate17.;	Tue, Jun 14, 2005

[Jennifer SUN]

Tue is 3 character

you just count the number of char including space and comma