The IS8601_CONVERT call routine converts an ISO 8601 interval to datetime and duration values, or converts datetime and duration values to an ISO 8601 interval. When the IS8601_CONVERT call routine computes a duration from two SAS datetime values, the computation might not be correct when the dates are not in consecutive months. The computation is correct when dates are in consecutive months.

The sample code on the Full Code tab illustrates the problem.

There is currently no circumvention for this issue.

Operating System and Release Information

Product Family	Product	System	SAS Release
			Reported	Fixed*
SAS System	Base SAS	Linux	9.2 TS1M0	9.4 TS1M6
		Linux for x64	9.2 TS1M0	9.4 TS1M6
		OpenVMS on HP Integrity	9.2 TS1M0	9.4 TS1M6
		Solaris for x64	9.2 TS1M0	9.4 TS1M6
		HP-UX IPF	9.2 TS1M0	9.4 TS1M6
		64-bit Enabled Solaris	9.2 TS1M0	9.4 TS1M6
		64-bit Enabled HP-UX	9.2 TS1M0	9.4 TS1M6
		64-bit Enabled AIX	9.2 TS1M0	9.4 TS1M6
		Windows Vista for x64	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	9.4 TS1M6
		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 64-bit	9.2 TS1M0	9.4 TS1M6
		z/OS	9.2 TS1M0	9.4 TS1M6

* 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.

The IS8601_CONVERT call routine can convert two SAS datetime values to a duration. The Start and End variables represent date values. Since we need SAS datetime values for the IS8601_CONVERT call routine parameters, Start and End values are read with the E8601DNw. informat to create SAS datetime values. An explanation of the parameters to the call routine follows:

1. The 'dt/dt' notation indicates that two datetime values are being supplied.
2. A duration is requested in the second argument.
3. The name of the first datetime variable.
4. The name of the second datetime variable.
5. Name of the new variable containing the resulting duration.

The duration value that is calculated is not in a readable format, so it needs to be formatted with the $N8601E format. The PUT statement writes the value to the SAS log.

---

data _null_;
   length _aedur $32.;
   start = '2017-10-04';
   startn = input(start,E8601DN. );
   end = '2017-12-01';
   endn = input(end,E8601DN. );
   CALL IS8601_CONVERT( 'dt/dt', 'du', startn, endn , _aedur);
   _aedur = put(_aedur,$N8601E.);
   put _aedur;
run;

The incorrect computed value is P1M28D.
The correct value should be P1M27D.

Type:	Problem Note
Priority:	high
Topic:	SAS Reference ==> CALL routines ==> IS8601_CONVERT

Date Modified:	2018-08-10 14:22:33
Date Created:	2018-08-08 11:14:38