IRAF Y2K Compliance


IRAF V2.11.3 is now available for all supported platforms and is the only Y2K compliant system. Users with older versions are likely to find problems creating new ".imh" images, "cannot open (String_File)" errors from various tasks which produce a date, or "incomplete or reentrant printf" errors. These messages can come either from core system or NOAO package tasks or external packages, for this reason users are strongly encouraged to upgrade as soon as possible and relink all external packages to pick up the necessary Y2K bug fixes.


The now familiar Year-2000 or "Y2K" problem is a result of many different software packages relying on two-digit representations of the year. This can cause any number of different bugs to appear when the century wraps around on 1 January 2000. There are many potential work-arounds for these bugs, but the only way to completely solve the problem is to modify each software package to understand and use four-digit year representations.

NOAO is required to submit quarterly Y2K reports to the NSF and this includes an analysis of IRAF's Y2K status and an implementation plan and schedule for fixing the small number of IRAF routines involved. This web page summarizes the steps being taken to ensure that IRAF is Y2K-compliant, and will be updated periodically as this this effort proceeds.

The majority of IRAF tasks will be unaffected by the Y2K problem. This includes most general purpose image processing tools as well as most astronomical reduction chores (flat fielding a CCD doesn't require the date, for instance). Those tasks that rely on the DATE-OBS keyword will need to be modified, however. This includes such areas as data acquisition and astrometry.

This is the same DATE-OBS problem that is faced by the FITS standard, since IRAF adopted the FITS keyword for its own use. You can read about the plans for resolving the problem in the FITS standard at:

The IRAF plan to support the provisions of this change to the FITS standard has been implemented and is in the process of being released in IRAF v2.11.2 and later patches for the various IRAF platforms.

While most IRAF tasks will be unaffected by the Y2K problem and the changes needed for the remaining tasks are well understood, unforeseen IRAF Y2K bugs are always possible, and some are expected in any large software system like IRAF. To assist in detecting and fixing such bugs we have taken the step of setting the clock forward on one of the IRAF workstations by 11 years, and periodically running a suite of IRAF tests on the machine. The 11 year time span was chosen since 2009 is the next year to use the same monthly calendar as 1998 - likewise 2010 will have the same calendar as 1999. This reduces the confusion of using the workstation during day-to-day testing. This testbed computer has been running time-shifted for over half a year with no major problems encountered in either Unix or IRAF.

IRAF V2.11.2 was thoroughly tested on this IRAF Y2K testbed prior to its initial release. We encountered and fixed one Y2K-related bug in v2.11.2 (this bug is also found in all older IRAF versions).

Further Y2K testing will take place on the Y2K testbed system for any further IRAF patches released during 1999. In addition, NOAO/IRAF will provide technical support including Y2K-related system patches to the IRAF developer community as the need arises. It is the responsibility of the individual projects to assess and address the Y2K compliance of their own layered IRAF software packages.


The IRAF V2.11.2 patch was released over the summer for selected platforms. The V2.11.3 patch is currently being prepared and will be released for all supported platforms during fall, 1999. All IRAF sites will need to update to versions later than V2.11.2 in order to be Y2K compliant. We will update this web page whenever there are any new Y2K-related developments.


IRAF Project
National Optical Astronomy Observatories
950 North Cherry Avenue
Tucson, Arizona 85719
(520) 318-8000
iraf@noao.edu

Updated: 2000-01-04